diff --git a/components/committee/CommitteeInterviewTimes.tsx b/components/committee/CommitteeInterviewTimes.tsx
index 88a98947..8bfd12f2 100644
--- a/components/committee/CommitteeInterviewTimes.tsx
+++ b/components/committee/CommitteeInterviewTimes.tsx
@@ -4,7 +4,7 @@ import { useSession } from "next-auth/react";
 import FullCalendar from "@fullcalendar/react";
 import timeGridPlugin from "@fullcalendar/timegrid";
 import interactionPlugin from "@fullcalendar/interaction";
-import { periodType, committeeInterviewType } from "../../lib/types/types";
+import { periodType, committeeInterviewType, AvailableTime } from "../../lib/types/types";
 import toast from "react-hot-toast";
 import NotFound from "../../pages/404";
 import Button from "../Button";
@@ -19,8 +19,8 @@ import { XMarkIcon } from "@heroicons/react/24/solid";
 interface Interview {
   id: string;
   title: string;
-  start: string;
-  end: string;
+  start: Date;
+  end: Date;
 }
 
 interface Props {
@@ -63,8 +63,8 @@ const CommitteeInterviewTimes = ({
   useEffect(() => {
     if (period) {
       setVisibleRange({
-        start: new Date(period!.interviewPeriod.start).toISOString(),
-        end: new Date(period!.interviewPeriod.end).toISOString(),
+        start: period.interviewPeriod.start.toISOString(),
+        end: period.interviewPeriod.end.toISOString(),
       });
     }
   }, [period]);
@@ -98,11 +98,11 @@ const CommitteeInterviewTimes = ({
       if (cleanCommittee === cleanSelectedCommittee) {
         setHasAlreadySubmitted(true);
         const events = committeeInterviewTimes.availabletimes.map(
-          (at: any) => ({
+          (availableTime: AvailableTime) => ({
             id: crypto.getRandomValues(new Uint32Array(1))[0].toString(),
-            title: at.room,
-            start: new Date(at.start).toISOString(),
-            end: new Date(at.end).toISOString(),
+            title: availableTime.room,
+            start: availableTime.start.toISOString(),
+            end: availableTime.end.toISOString(),
           })
         );
 
@@ -262,17 +262,12 @@ const CommitteeInterviewTimes = ({
     );
   };
 
-  const formatEventsForExport = (events: Interview[]) => {
-    return events.map((event) => {
-      const startDateTime = new Date(event.start);
-      const endDateTime = new Date(event.end);
-      return {
+  const formatEventsForExport = (events: Interview[]) => 
+    events.map((event) => ({
         room: event.title,
-        start: startDateTime.toISOString(),
-        end: endDateTime.toISOString(),
-      };
-    });
-  };
+        start: event.start.toISOString(),
+        end: event.end.toISOString(),
+    }));
 
   const handleTimeslotSelection = (e: React.ChangeEvent<HTMLSelectElement>) => {
     setSelectedTimeslot(e.target.value);
diff --git a/components/form/DatePickerInput.tsx b/components/form/DatePickerInput.tsx
index 6ef4474c..9cd0f3a1 100644
--- a/components/form/DatePickerInput.tsx
+++ b/components/form/DatePickerInput.tsx
@@ -1,7 +1,10 @@
 import { useEffect, useState } from "react";
+import { fromZonedTime } from 'date-fns-tz';
+import { timezone } from "../../lib/utils/dateUtils";
+
 interface Props {
   label?: string;
-  updateDates: (dates: { start: string; end: string }) => void;
+  updateDates: (dates: { start: Date; end: Date }) => void;
 }
 
 const DatePickerInput = (props: Props) => {
@@ -9,8 +12,19 @@ const DatePickerInput = (props: Props) => {
   const [toDate, setToDate] = useState("");
 
   useEffect(() => {
-    const startDate = fromDate ? `${fromDate}T00:00` : "";
-    const endDate = toDate ? `${toDate}T23:59` : "";
+    if (!fromDate || !toDate) return;
+
+
+    // Convert to Date objects in correct timezone
+    const startDate = fromZonedTime(
+      `${fromDate}T00:00:00`,
+      timezone
+    );
+    const endDate = fromZonedTime(
+      `${toDate}T23:59:59`,
+      timezone
+    );
+
     props.updateDates({ start: startDate, end: endDate });
   }, [fromDate, toDate]);
 
@@ -38,8 +52,11 @@ const DatePickerInput = (props: Props) => {
           className="border text-sm rounded-lg focus:ring-blue-500 focus:border-blue-500 block w-full p-2.5 border-gray-300 text-gray-900 dark:border-gray-600 dark:bg-online-darkBlue dark:text-gray-200"
         />
       </div>
+      <p className="mt-1.5 text-xs text-gray-500 dark:text-gray-400">
+        NB: Alle tider er i norsk tidssone (GMT+1)
+      </p>
     </div>
   );
 };
 
-export default DatePickerInput;
+export default DatePickerInput;
\ No newline at end of file
diff --git a/lib/mongo/applicants.ts b/lib/mongo/applicants.ts
index 212aff32..b5522b25 100644
--- a/lib/mongo/applicants.ts
+++ b/lib/mongo/applicants.ts
@@ -1,7 +1,8 @@
 import { Collection, Db, MongoClient, ObjectId } from "mongodb";
 import clientPromise from "./mongodb";
-import { applicantType, periodType, preferencesType } from "../types/types";
+import { applicantType, Nullable, periodType, preferencesType } from "../types/types";
 import { getPeriodById } from "./periods";
+import { addDays, isAfter } from 'date-fns';
 
 let client: MongoClient;
 let db: Db;
@@ -153,7 +154,7 @@ export const getApplicantsForCommittee = async (
     // Filtrerer søkerne slik at kun brukere som er i komiteen som har blitt søkt på ser søkeren
     // Fjerner prioriterings informasjon
     const filteredApplicants = result
-      .map((applicant) => {
+      .map((applicant: Nullable<applicantType>) => {
         let preferencesArray: string[] = [];
         if (isPreferencesType(applicant.preferences)) {
           preferencesArray = [
@@ -182,24 +183,22 @@ export const getApplicantsForCommittee = async (
 
         applicant.optionalCommittees = [];
 
-        const today = new Date();
-        const sevenDaysAfterInterviewEnd = new Date(period.interviewPeriod.end);
-        sevenDaysAfterInterviewEnd.setDate(
-          sevenDaysAfterInterviewEnd.getDate() + 5
-        );
+        const now = new Date();
+        const sevenDaysAfterInterviewEnd = addDays(period.interviewPeriod.end, 7);
 
+        // Sletter sensitiv informasjon etter intervju perioden + 7 dager, for å forhindre snoking i tidligere søknader
         if (
-          new Date(period.applicationPeriod.end) > today ||
-          today > sevenDaysAfterInterviewEnd
+          isAfter(now, period.applicationPeriod.end) ||
+          isAfter(now, sevenDaysAfterInterviewEnd)
         ) {
-          applicant.owId = "Skjult";
-          applicant.name = "Skjult";
-          applicant.date = today;
-          applicant.phone = "Skjult";
-          applicant.email = "Skjult";
-          applicant.about = "Skjult";
-          applicant.grade = "-";
-          applicant.selectedTimes = [{ start: "Skjult", end: "Skjult" }];
+          applicant.owId = null;
+          applicant.name = null;
+          applicant.phone = null;
+          applicant.grade = null;
+          applicant.email = null;
+          applicant.about = null;
+          applicant.selectedTimes = null;
+          applicant.date = null;
         }
 
         const isSelectedCommitteePresent =
diff --git a/lib/mongo/committees.ts b/lib/mongo/committees.ts
index e978fef6..aa83707b 100644
--- a/lib/mongo/committees.ts
+++ b/lib/mongo/committees.ts
@@ -1,4 +1,4 @@
-import { Collection, Db, MongoClient, ObjectId, UpdateResult } from "mongodb";
+import { Collection, Db, MongoClient, ObjectId } from "mongodb";
 import clientPromise from "./mongodb";
 import { committeeInterviewType } from "../types/types";
 
diff --git a/lib/mongo/periods.ts b/lib/mongo/periods.ts
index dccc87d8..e40814b3 100644
--- a/lib/mongo/periods.ts
+++ b/lib/mongo/periods.ts
@@ -59,19 +59,19 @@ export const getCurrentPeriods = async () => {
   try {
     if (!periods) await init();
 
-    const currentDate = new Date().toISOString();
+    const now = new Date();
 
     const filter = {
       $or: [
         {
-          // Check if current ISO date string is within the application period
-          "applicationPeriod.start": { $lte: currentDate },
-          "applicationPeriod.end": { $gte: currentDate },
+          // Check if current date is within the application period
+          "applicationPeriod.start": { $lte: now },
+          "applicationPeriod.end": { $gte: now },
         },
         {
-          // Check if current ISO date string is within the interview period
-          "interviewPeriod.start": { $lte: currentDate },
-          "interviewPeriod.end": { $gte: currentDate },
+          // Check if current date is within the interview period
+          "interviewPeriod.start": { $lte: now },
+          "interviewPeriod.end": { $gte: now },
         },
       ],
     };
diff --git a/lib/sendInterviewTimes/formatInterviewEmail.ts b/lib/sendInterviewTimes/formatInterviewEmail.ts
index b6b91d9f..80282cf1 100644
--- a/lib/sendInterviewTimes/formatInterviewEmail.ts
+++ b/lib/sendInterviewTimes/formatInterviewEmail.ts
@@ -1,3 +1,4 @@
+import { compareAsc } from "date-fns";
 import {
   emailApplicantInterviewType,
   emailCommitteeInterviewType,
@@ -11,25 +12,22 @@ export const formatApplicantInterviewEmail = (
 ) => {
   let emailBody = `<p>Hei <strong>${applicant.applicantName}</strong>,</p><p>Her er dine intervjutider for ${applicant.period_name}:</p><ul><br/>`;
 
-  applicant.committees.sort((a, b) => {
-    return (
-      new Date(a.interviewTime.start).getTime() -
-      new Date(b.interviewTime.start).getTime()
-    );
-  });
+  // Sort committees by interview start time
+  applicant.committees.sort((a, b) => 
+    compareAsc(a.interviewTime.start, b.interviewTime.start)
+  );
 
   applicant.committees.forEach((committee) => {
     emailBody += `<li><b>Komité:</b> ${changeDisplayName(
       committee.committeeName
     )}<br>`;
 
-    if (committee.interviewTime.start !== "Ikke satt") {
+    if (committee.interviewTime.start != null) {
       emailBody += `<b>Tid:</b> ${formatDateHours(
         committee.interviewTime.start,
         committee.interviewTime.end
       )}<br>`;
-    }
-    if (committee.interviewTime.start === "Ikke satt") {
+    } else {
       emailBody += `<b>Tid:</b> Ikke satt. Komitéen vil ta kontakt med deg for å avtale tidspunkt.<br>`;
     }
 
@@ -50,25 +48,21 @@ export const formatCommitteeInterviewEmail = (
     committee.applicants.length
   } søkere:</p><ul>`;
 
-  committee.applicants.sort((a, b) => {
-    return (
-      new Date(a.interviewTime.start).getTime() -
-      new Date(b.interviewTime.start).getTime()
-    );
-  });
+  // Sort applicants by interview start time
+  committee.applicants.sort((a, b) => 
+    compareAsc(a.interviewTime.start, b.interviewTime.start)
+  );
 
   committee.applicants.forEach((applicant) => {
     emailBody += `<li><b>Navn:</b> ${applicant.applicantName}<br>`;
     emailBody += `<b>Telefon:</b> ${applicant.applicantPhone} <br> `;
 
-    if (applicant.interviewTime.start !== "Ikke satt") {
+    if (applicant.interviewTime.start != null) {
       emailBody += `<b>Tid:</b> ${formatDateHours(
         applicant.interviewTime.start,
         applicant.interviewTime.end
       )}<br>`;
-    }
-
-    if (applicant.interviewTime.start === "Ikke satt") {
+    } else {
       emailBody += `<b>Tid:</b> Ikke satt. Ta kontakt med søker for å avtale tidspunkt.`;
     }
     emailBody += `<b>Rom:</b> ${applicant.interviewTime.room}</li><br>`;
diff --git a/lib/sendInterviewTimes/formatInterviewSMS.ts b/lib/sendInterviewTimes/formatInterviewSMS.ts
index e9b42822..08e5de91 100644
--- a/lib/sendInterviewTimes/formatInterviewSMS.ts
+++ b/lib/sendInterviewTimes/formatInterviewSMS.ts
@@ -1,3 +1,4 @@
+import { compareAsc } from "date-fns";
 import { emailApplicantInterviewType } from "../types/types";
 import { formatDateHours } from "../utils/dateUtils";
 import { changeDisplayName } from "../utils/toString";
@@ -5,24 +6,20 @@ import { changeDisplayName } from "../utils/toString";
 export const formatInterviewSMS = (applicant: emailApplicantInterviewType) => {
   let phoneBody = `Hei ${applicant.applicantName}, her er dine intervjutider for ${applicant.period_name}: \n \n`;
 
-  applicant.committees.sort((a, b) => {
-    return (
-      new Date(a.interviewTime.start).getTime() -
-      new Date(b.interviewTime.start).getTime()
-    );
-  });
+  // Sort committees by interview start time
+  applicant.committees.sort((a, b) => 
+    compareAsc(a.interviewTime.start, b.interviewTime.start)
+  );
 
   applicant.committees.forEach((committee) => {
     phoneBody += `Komité: ${changeDisplayName(committee.committeeName)} \n`;
 
-    if (committee.interviewTime.start !== "Ikke satt") {
+    if (committee.interviewTime.start != null) {
       phoneBody += `Tid: ${formatDateHours(
         committee.interviewTime.start,
         committee.interviewTime.end
       )}\n`;
-    }
-
-    if (committee.interviewTime.start === "Ikke satt") {
+    } else {
       phoneBody += `Tid: Ikke satt. Komitéen vil ta kontakt for å avtale tidspunkt. \n`;
     }
 
diff --git a/lib/types/types.ts b/lib/types/types.ts
index dced56e7..897012c0 100644
--- a/lib/types/types.ts
+++ b/lib/types/types.ts
@@ -4,6 +4,10 @@ export type DeepPartial<T> = {
   [P in keyof T]?: T[P] extends object ? DeepPartial<T[P]> : T[P];
 };
 
+export type Nullable<T> = {
+  [K in keyof T]: T[K] | null;
+}
+
 export type preferencesType = {
   first: string;
   second: string;
@@ -27,8 +31,8 @@ export type applicantType = {
   optionalCommittees: string[];
   selectedTimes: [
     {
-      start: string;
-      end: string;
+      start: Date;
+      end: Date;
     },
   ];
   date: Date;
@@ -69,8 +73,8 @@ export type periodType = {
 };
 
 export type AvailableTime = {
-  start: string;
-  end: string;
+  start: Date;
+  end: Date;
   room: string;
 };
 
@@ -80,7 +84,7 @@ export type committeeInterviewType = {
   committee: string;
   committeeEmail: string;
   availabletimes: AvailableTime[];
-  timeslot: string;
+  timeslot: string; // duration of each interview in minutes
   message: string;
 };
 
@@ -110,8 +114,8 @@ export interface OwGroup {
 export type algorithmType = {
   applicantId: string;
   interviews: {
-    start: string;
-    end: string;
+    start: Date;
+    end: Date;
     committeeName: string;
     room: string;
   }[];
@@ -132,8 +136,8 @@ export type emailCommitteeInterviewType = {
     applicantPhone: string;
     applicantEmail: string;
     interviewTime: {
-      start: string;
-      end: string;
+      start: Date;
+      end: Date;
       room: string;
     };
   }[];
@@ -149,8 +153,8 @@ export type emailApplicantInterviewType = {
     committeeName: string;
     committeeEmail: string;
     interviewTime: {
-      start: string;
-      end: string;
+      start: Date;
+      end: Date;
       room: string;
     };
   }[];
diff --git a/lib/utils/dateUtils.ts b/lib/utils/dateUtils.ts
index 8ab5de14..ab9f1cfd 100644
--- a/lib/utils/dateUtils.ts
+++ b/lib/utils/dateUtils.ts
@@ -1,55 +1,32 @@
-export const formatDate = (inputDate: undefined | Date) => {
-  const date = new Date(inputDate || "");
+import { isBefore, isAfter, isEqual } from 'date-fns';
+import { formatInTimeZone } from 'date-fns-tz';
+import { nb } from 'date-fns/locale';
 
-  const day = date.getDate().toString().padStart(2, "0");
-  const month = (date.getMonth() + 1).toString().padStart(2, "0");
-  const year = date.getFullYear();
-  const hours = date.getHours().toString().padStart(2, "0");
-  const minutes = date.getMinutes().toString().padStart(2, "0");
+export const timezone = 'Europe/Oslo'; // Norwegian Time Zone
 
-  return `${day}.${month}.${year}`; //  - ${hours}:${minutes}
+export const formatDate = (inputDate: undefined | Date) => {
+  if (!inputDate) return "";
+  
+  return formatInTimeZone(inputDate, timezone, 'dd.MM.yyyy'); // - HH:mm
 };
 
-export const formatDateHours = (
-  start: string,
-  end: string
-) => {
-  const startDate = new Date(Date.parse(start));
-
-  const startTime = start.split("T")[1].slice(0, 5);
-  const endTime = end.split("T")[1].slice(0, 5);
+export const formatDateHours = (start: Date, end: Date): string => {
 
-  return `${formatDateNorwegian(
-    startDate
-  )}, ${startTime} til ${endTime}`;
+  const dateStr = formatInTimeZone(start, timezone, 'd. MMMM yyyy', { locale: nb });
+  const startTime = formatInTimeZone(start, timezone, 'HH:mm');
+  const endTime = formatInTimeZone(end, timezone, 'HH:mm');
+  
+  return `${dateStr}, ${startTime} til ${endTime}`;
 };
 
-export const formatDateNorwegian = (inputDate?: Date | string) => {
+export const formatDateNorwegian = (inputDate: Date): string => {
   if (!inputDate) return "";
+  
+  return formatInTimeZone(inputDate, timezone, 'd. MMM', { locale: nb });
+};
 
-  let date: Date;
-  if (inputDate instanceof Date) {
-    date = inputDate;
-  } else {
-    date = new Date(inputDate);
-  }
-
-  const day = date.getUTCDate().toString().padStart(2, "0");
-  const monthsNorwegian = [
-    "jan",
-    "feb",
-    "mar",
-    "apr",
-    "mai",
-    "jun",
-    "jul",
-    "aug",
-    "sep",
-    "okt",
-    "nov",
-    "des",
-  ];
-  const month = monthsNorwegian[date.getUTCMonth()];
+export const isBeforeOrEqual = (date: Date, dateToCompare: Date) => 
+  isBefore(date, dateToCompare) || isEqual(date, dateToCompare);
 
-  return `${day}. ${month}`;
-};
+export const isAfterOrEqual = (date: Date, dateToCompare: Date) => 
+  isAfter(date, dateToCompare) || isEqual(date, dateToCompare);
\ No newline at end of file
diff --git a/lib/utils/validateApplication.ts b/lib/utils/validateApplication.ts
index eada7a89..0fc6e012 100644
--- a/lib/utils/validateApplication.ts
+++ b/lib/utils/validateApplication.ts
@@ -71,8 +71,8 @@ export const validateApplication = (applicationData: any) => {
   }
 
   for (const time of selectedTimes) {
-    const startTime = new Date(time.start);
-    const endTime = new Date(time.end);
+    const startTime = time.start;
+    const endTime = time.end;
     if (isNaN(startTime.getTime()) || isNaN(endTime.getTime())) {
       toast.error("Ugyldig start- eller sluttid");
       return false;
diff --git a/lib/utils/validators.ts b/lib/utils/validators.ts
index e4433c4f..1eefcd56 100644
--- a/lib/utils/validators.ts
+++ b/lib/utils/validators.ts
@@ -4,6 +4,7 @@ import {
   periodType,
   preferencesType,
 } from "../types/types";
+import { isBeforeOrEqual } from "./dateUtils";
 
 export const isApplicantType = (
   applicant: applicantType,
@@ -59,14 +60,12 @@ export const isApplicantType = (
   const hasSelectedTimes =
     Array.isArray(applicant.selectedTimes) &&
     applicant.selectedTimes.every(
-      (time: { start: string; end: string }) =>
-        typeof time.start === "string" &&
-        typeof time.end === "string" &&
-        new Date(time.start) >= interviewPeriodStart &&
-        new Date(time.start) <= interviewPeriodEnd &&
-        new Date(time.end) <= interviewPeriodEnd &&
-        new Date(time.end) >= interviewPeriodStart &&
-        new Date(time.start) < new Date(time.end)
+      (time: { start: Date; end: Date }) =>
+        time.start >= interviewPeriodStart &&
+        time.start <= interviewPeriodEnd &&
+        time.end <= interviewPeriodEnd &&
+        time.end >= interviewPeriodStart &&
+        time.start < time.end
     );
 
   const periodOptionalCommittees = period.optionalCommittees.map((committee) =>
@@ -117,7 +116,8 @@ export const validateCommittee = (data: any, period: periodType): boolean => {
 
   const isPeriodNameValid = data.periodId === String(period._id);
 
-  const isBeforeDeadline = new Date() <= new Date(period.applicationPeriod.end);
+  const now = new Date();
+  const isBeforeDeadline = isBeforeOrEqual(now, period.applicationPeriod.end);
 
   const committeeExists =
     period.committees.some((committee) => {
@@ -128,15 +128,15 @@ export const validateCommittee = (data: any, period: periodType): boolean => {
     });
 
   const isWithinInterviewPeriod = data.availabletimes.every(
-    (time: { start: string; end: string }) => {
-      const startTime = new Date(time.start);
-      const endTime = new Date(time.end);
+    (time: { start: Date; end: Date }) => {
+      const startTime = time.start;
+      const endTime = time.end;
 
       return (
-        startTime >= new Date(period.interviewPeriod.start) &&
-        startTime <= new Date(period.interviewPeriod.end) &&
-        endTime <= new Date(period.interviewPeriod.end) &&
-        endTime >= new Date(period.interviewPeriod.start) &&
+        startTime >= period.interviewPeriod.start &&
+        startTime <= period.interviewPeriod.end &&
+        endTime <= period.interviewPeriod.end &&
+        endTime >= period.interviewPeriod.start &&
         startTime < endTime
       );
     }
@@ -152,31 +152,27 @@ export const validateCommittee = (data: any, period: periodType): boolean => {
 };
 
 export const isPeriodType = (data: any): data is periodType => {
-  const isDateString = (str: any): boolean => {
-    return typeof str === "string" && !isNaN(Date.parse(str));
-  };
+  const isDateDate = (date: any): boolean => {
+    return date instanceof Date && !isNaN(date.getTime());
+  }
 
   const isValidPeriod = (period: any): boolean => {
     return (
       typeof period === "object" &&
       period !== null &&
-      isDateString(period.start) &&
-      isDateString(period.end)
+      isDateDate(period.start) &&
+      isDateDate(period.end)
     );
   };
 
-  const isChronological = (start: string, end: string): boolean => {
-    return new Date(start) <= new Date(end);
-  };
-
   const arePeriodsValid = (
     applicationPeriod: any,
     interviewPeriod: any
   ): boolean => {
     return (
-      isChronological(applicationPeriod.start, applicationPeriod.end) &&
-      isChronological(interviewPeriod.start, interviewPeriod.end) &&
-      new Date(applicationPeriod.end) <= new Date(interviewPeriod.start)
+      isBeforeOrEqual(applicationPeriod.start, applicationPeriod.end) &&
+      isBeforeOrEqual(interviewPeriod.start, interviewPeriod.end) &&
+      isBeforeOrEqual(applicationPeriod.end, interviewPeriod.start)
     );
   };
 
diff --git a/package-lock.json b/package-lock.json
index 973ad124..18f8226f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -22,6 +22,8 @@
         "@trpc/tanstack-react-query": "^11.6.0",
         "@types/mongodb": "^4.0.7",
         "@vercel/analytics": "^1.1.2",
+        "date-fns": "^4.1.0",
+        "date-fns-tz": "^3.2.0",
         "dompurify": "^3.3.1",
         "lucide-react": "^0.441.0",
         "mongodb": "^6.1.0",
@@ -2705,6 +2707,25 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/date-fns": {
+      "version": "4.1.0",
+      "resolved": "https://registry.npmjs.org/date-fns/-/date-fns-4.1.0.tgz",
+      "integrity": "sha512-Ukq0owbQXxa/U3EGtsdVBkR1w7KOQ5gIBqdH2hkvknzZPYvBxb/aa6E8L7tmjFtkwZBu3UXBbjIgPo/Ez4xaNg==",
+      "license": "MIT",
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/kossnocorp"
+      }
+    },
+    "node_modules/date-fns-tz": {
+      "version": "3.2.0",
+      "resolved": "https://registry.npmjs.org/date-fns-tz/-/date-fns-tz-3.2.0.tgz",
+      "integrity": "sha512-sg8HqoTEulcbbbVXeg84u5UnlsQa8GS5QXMqjjYIhS4abEVVKIUwe0/l/UhrZdKaL/W5eWZNlbTeEIiOXTcsBQ==",
+      "license": "MIT",
+      "peerDependencies": {
+        "date-fns": "^3.0.0 || ^4.0.0"
+      }
+    },
     "node_modules/dayjs": {
       "version": "1.11.13",
       "resolved": "https://registry.npmjs.org/dayjs/-/dayjs-1.11.13.tgz",
diff --git a/package.json b/package.json
index b3a00bfc..e6fdb1d3 100644
--- a/package.json
+++ b/package.json
@@ -25,6 +25,8 @@
     "@trpc/tanstack-react-query": "^11.6.0",
     "@types/mongodb": "^4.0.7",
     "@vercel/analytics": "^1.1.2",
+    "date-fns": "^4.1.0",
+    "date-fns-tz": "^3.2.0",
     "dompurify": "^3.3.1",
     "lucide-react": "^0.441.0",
     "mongodb": "^6.1.0",
diff --git a/pages/admin/new-period.tsx b/pages/admin/new-period.tsx
index 48833a38..d8244684 100644
--- a/pages/admin/new-period.tsx
+++ b/pages/admin/new-period.tsx
@@ -83,14 +83,14 @@ const NewPeriod = () => {
     start,
     end,
   }: {
-    start: string;
-    end: string;
+    start: Date;
+    end: Date;
   }) => {
     setPeriodData((prevData) => ({
       ...prevData,
       applicationPeriod: {
-        start: start ? new Date(start) : undefined,
-        end: end ? new Date(end) : undefined,
+        start: start,
+        end: end,
       },
     }));
   };
@@ -99,14 +99,14 @@ const NewPeriod = () => {
     start,
     end,
   }: {
-    start: string;
-    end: string;
+    start: Date;
+    end: Date;
   }) => {
     setPeriodData((prevData) => ({
       ...prevData,
       interviewPeriod: {
-        start: start ? new Date(start) : undefined,
-        end: end ? new Date(end) : undefined,
+        start: start,
+        end: end,
       },
     }));
   };
diff --git a/pages/api/applicants/[period-id]/[id].ts b/pages/api/applicants/[period-id]/[id].ts
index 3c391e1b..e2799a5f 100644
--- a/pages/api/applicants/[period-id]/[id].ts
+++ b/pages/api/applicants/[period-id]/[id].ts
@@ -7,10 +7,10 @@ import { getServerSession } from "next-auth";
 import { authOptions } from "../../auth/[...nextauth]";
 import {
   hasSession,
-  isAdmin,
   checkOwId,
 } from "../../../../lib/utils/apiChecks";
 import { getPeriodById } from "../../../../lib/mongo/periods";
+import { isBefore } from "date-fns";
 
 const handler = async (req: NextApiRequest, res: NextApiResponse) => {
   const session = await getServerSession(req, res, authOptions);
@@ -40,9 +40,9 @@ const handler = async (req: NextApiRequest, res: NextApiResponse) => {
       }
       return res.status(200).json({ exists, application });
     } else if (req.method === "DELETE") {
-      const currentDate = new Date().toISOString();
+      const now = new Date();
 
-      if (new Date(period.applicationPeriod.end) < new Date(currentDate)) {
+      if (isBefore(period.applicationPeriod.end, now)) {
         return res.status(403).json({ error: "Application period is over" });
       }
 
diff --git a/pages/api/applicants/index.ts b/pages/api/applicants/index.ts
index ee6440cb..20d06878 100644
--- a/pages/api/applicants/index.ts
+++ b/pages/api/applicants/index.ts
@@ -8,6 +8,7 @@ import { isApplicantType } from "../../../lib/utils/validators";
 import { isAdmin, hasSession, checkOwId } from "../../../lib/utils/apiChecks";
 import { sendConfirmationSMS } from "../../../lib/sms/sendConfirmationSMS";
 import { sendConfirmationEmail } from "../../../lib/email/sendConfirmationEmail";
+import { isAfter, isBefore } from "date-fns";
 
 const handler = async (req: NextApiRequest, res: NextApiResponse) => {
   const session = await getServerSession(req, res, authOptions);
@@ -25,7 +26,6 @@ const handler = async (req: NextApiRequest, res: NextApiResponse) => {
 
     if (req.method === "POST") {
       const requestBody: applicantType = req.body;
-      requestBody.date = new Date(new Date().getTime() + 60 * 60 * 2000); // add date with norwegain time (GMT+2)
 
       const { period } = await getPeriodById(String(requestBody.periodId));
 
@@ -44,7 +44,7 @@ const handler = async (req: NextApiRequest, res: NextApiResponse) => {
       const applicationEnd = period.applicationPeriod.end;
 
       // Check if the current time is within the application period
-      if (now < applicationStart || now > applicationEnd) {
+      if (isBefore(now, applicationStart) || isAfter(now, applicationEnd)) {
         return res
           .status(400)
           .json({ error: "Not within the application period" });
diff --git a/pages/api/committees/times/[period-id]/[committee].ts b/pages/api/committees/times/[period-id]/[committee].ts
index 573b31ed..4f62f3ab 100644
--- a/pages/api/committees/times/[period-id]/[committee].ts
+++ b/pages/api/committees/times/[period-id]/[committee].ts
@@ -7,6 +7,7 @@ import { getServerSession } from "next-auth";
 import { authOptions } from "../../../auth/[...nextauth]";
 import { hasSession, isInCommitee } from "../../../../../lib/utils/apiChecks";
 import { getPeriodById } from "../../../../../lib/mongo/periods";
+import { isAfter } from "date-fns";
 
 const handler = async (req: NextApiRequest, res: NextApiResponse) => {
   const session = await getServerSession(req, res, authOptions);
@@ -50,7 +51,9 @@ const handler = async (req: NextApiRequest, res: NextApiResponse) => {
         return res.status(400).json({ error: "Invalid periodId" });
       }
 
-      if (new Date() > new Date(period.applicationPeriod.end)) {
+      const now = new Date();
+
+      if (isAfter(now, period.interviewPeriod.end)) {
         return res.status(400).json({ error: "Application period has ended" });
       }
 
diff --git a/pages/api/committees/times/[period-id]/index.ts b/pages/api/committees/times/[period-id]/index.ts
index 297a0016..5ffeb089 100644
--- a/pages/api/committees/times/[period-id]/index.ts
+++ b/pages/api/committees/times/[period-id]/index.ts
@@ -9,6 +9,7 @@ import {
 } from "../../../../../lib/utils/validators";
 import { getPeriodById } from "../../../../../lib/mongo/periods";
 import { committeeInterviewType } from "../../../../../lib/types/types";
+import { isAfter } from "date-fns";
 
 const handler = async (req: NextApiRequest, res: NextApiResponse) => {
   const session = await getServerSession(req, res, authOptions);
@@ -35,7 +36,9 @@ const handler = async (req: NextApiRequest, res: NextApiResponse) => {
       return res.status(400).json({ error: "Invalid periodId" });
     }
 
-    if (new Date() > new Date(period.applicationPeriod.end)) {
+    const now = new Date();
+
+    if (isAfter(now, period.interviewPeriod.end)) {
       return res.status(400).json({ error: "Application period has ended" });
     }
 
diff --git a/pages/apply/[period-id].tsx b/pages/apply/[period-id].tsx
index 2f6836e3..be66a641 100644
--- a/pages/apply/[period-id].tsx
+++ b/pages/apply/[period-id].tsx
@@ -25,6 +25,7 @@ import {
 import ErrorPage from "../../components/ErrorPage";
 import { MainTitle, SimpleTitle } from "../../components/Typography";
 import { getCommitteeDisplayNameFactory } from "../../lib/utils/getCommitteeDisplayNameFactory";
+import { isBefore } from "date-fns";
 
 const Application: NextPage = () => {
   const queryClient = useQueryClient();
@@ -116,9 +117,9 @@ const Application: NextPage = () => {
 
     setPeriod(periodData.period);
 
-    const currentDate = new Date().toISOString();
+    const now = new Date();
     if (
-      new Date(periodData.period.applicationPeriod.end) < new Date(currentDate)
+      isBefore(periodData.period.applicationPeriod.end, now)
     ) {
       setIsApplicationPeriodOver(true);
     }
@@ -160,7 +161,7 @@ const Application: NextPage = () => {
     return <LoadingPage />;
   if (periodIsError || applicantIsError) return <ErrorPage />;
 
-  if (!periodData?.exists)
+  if (!periodData?.exists || !period)
     return <SimpleTitle title="Opptaket finnes ikke" size="large" />;
 
   if (fetchedApplicationData?.exists)
@@ -173,7 +174,7 @@ const Application: NextPage = () => {
         </p>
         <p className="max-w-md text-lg text-center">
           Du vil få enda en e-post med intervjutider når søknadsperioden er over
-          (rundt {formatDateNorwegian(period?.applicationPeriod?.end)}).
+          (rundt {formatDateNorwegian(period?.applicationPeriod.end)}).
         </p>
         <p className="max-w-md text-center text-gray-500">
           (Hvis du ikke finner e-posten din, sjekk søppelpost- eller
diff --git a/pages/apply/index.tsx b/pages/apply/index.tsx
index 4a7867bf..78851fd9 100644
--- a/pages/apply/index.tsx
+++ b/pages/apply/index.tsx
@@ -7,6 +7,7 @@ import { fetchPeriods } from "../../lib/api/periodApi";
 import { periodType } from "../../lib/types/types";
 import { PeriodSkeletonPage } from "../../components/PeriodSkeleton";
 import { SimpleTitle } from "../../components/Typography";
+import { isAfterOrEqual, isBeforeOrEqual } from "../../lib/utils/dateUtils";
 
 const Apply = () => {
   const [currentPeriods, setCurrentPeriods] = useState<periodType[]>([]);
@@ -24,23 +25,19 @@ const Apply = () => {
   useEffect(() => {
     if (!periodsData) return;
 
-    const today = new Date();
+    const now = new Date();
 
     setCurrentPeriods(
       periodsData.periods.filter((period: periodType) => {
-        const startDate = new Date(period.applicationPeriod.start || "");
-        const endDate = new Date(period.applicationPeriod.end || "");
+        const startDate = period.applicationPeriod.start;
+        const endDate = period.applicationPeriod.end;
 
-        return startDate <= today && endDate >= today;
+        return isBeforeOrEqual(startDate, now) && isAfterOrEqual(endDate, now);
       })
     );
 
     setUpcomingPeriods(
-      periodsData.periods.filter((period: periodType) => {
-        const startDate = new Date(period.applicationPeriod.start || "");
-
-        return startDate >= today
-      })
+      periodsData.periods.filter((period: periodType) => isAfterOrEqual(period.applicationPeriod.start, now))
     )
   }, [periodsData]);
 
diff --git a/pages/committee/[period-id]/[committee]/index.tsx b/pages/committee/[period-id]/[committee]/index.tsx
index b5f51989..510147d0 100644
--- a/pages/committee/[period-id]/[committee]/index.tsx
+++ b/pages/committee/[period-id]/[committee]/index.tsx
@@ -9,7 +9,6 @@ import { useRouter } from "next/router";
 import ApplicantsOverview from "../../../../components/applicantoverview/ApplicantsOverview";
 import {
   CalendarIcon,
-  InboxIcon,
   UserGroupIcon,
 } from "@heroicons/react/24/solid";
 import { Tabs } from "../../../../components/Tabs";
@@ -23,6 +22,7 @@ import { fetchPeriodById } from "../../../../lib/api/periodApi";
 import ErrorPage from "../../../../components/ErrorPage";
 import { fetchCommitteeTimes } from "../../../../lib/api/committeesApi";
 import { MainTitle, SimpleTitle } from "../../../../components/Typography";
+import { addDays, isBefore } from "date-fns";
 
 const CommitteeApplicantOverview: NextPage = () => {
   const { data: session } = useSession();
@@ -82,15 +82,11 @@ const CommitteeApplicantOverview: NextPage = () => {
   if (periodIsError || interviewTimesIsError) return <ErrorPage />;
   if (!hasAccess) return <Custom404 />;
 
-  const interviewPeriodEnd = period?.interviewPeriod.end
-    ? new Date(period.interviewPeriod.end)
-    : null;
-
   // Satt frist til 14 dager etter intervju perioden, så får man ikke tilgang
-  const interviewAccessExpired =
-    interviewPeriodEnd &&
-    interviewPeriodEnd.getTime() + 14 * 24 * 60 * 60 * 1000 <
-      new Date().getTime();
+
+  const now = new Date();
+  const fourteenDaysAfterInterview = addDays(period.interviewPeriod.end, 14);
+  const interviewAccessExpired = isBefore(fourteenDaysAfterInterview, now);
 
   if (interviewAccessExpired) {
     return (
diff --git a/pages/committees.tsx b/pages/committees.tsx
index b658841c..5c9f14e9 100644
--- a/pages/committees.tsx
+++ b/pages/committees.tsx
@@ -11,6 +11,7 @@ import { UsersIcon } from "@heroicons/react/24/outline";
 import { Tabs } from "../components/Tabs";
 import { UserIcon, BellAlertIcon } from "@heroicons/react/24/solid";
 import { shuffleList, partition } from "../lib/utils/arrays";
+import { isAfterOrEqual, isBeforeOrEqual } from "../lib/utils/dateUtils";
 
 // Page Component
 export default function Committees() {
@@ -103,17 +104,17 @@ export default function Committees() {
           },
           ...(committeesInActivePeriod.length > 0
             ? [
-                {
-                  title: "Har opptak",
-                  icon: <BellAlertIcon className="w-5 h-5" />,
-                  content: (
-                    <CommitteeList
-                      committees={committeesInActivePeriod}
-                      periods={periods}
-                    />
-                  ),
-                },
-              ]
+              {
+                title: "Har opptak",
+                icon: <BellAlertIcon className="w-5 h-5" />,
+                content: (
+                  <CommitteeList
+                    committees={committeesInActivePeriod}
+                    periods={periods}
+                  />
+                ),
+              },
+            ]
             : []),
         ]}
       />
@@ -165,12 +166,12 @@ const committeeIsInActivePeriod = (
 ) => {
   if (!Array.isArray(periods)) return false;
 
-  const today = new Date();
+  const now = new Date();
 
   const activePeriods = periods.filter((period) => {
-    const applicationStart = new Date(period.applicationPeriod.start);
-    const applicationEnd = new Date(period.applicationPeriod.end);
-    return applicationStart <= today && applicationEnd >= today;
+    const applicationStart = period.applicationPeriod.start;
+    const applicationEnd = period.applicationPeriod.end;
+    return isBeforeOrEqual(applicationStart, now) && isAfterOrEqual(applicationEnd, now);
   });
 
   // Bankom is always active, since you can be a representative of bankom from each committee
@@ -191,12 +192,12 @@ const committeeIsCurrentlyInterviewing = (
 ) => {
   if (!Array.isArray(periods)) return false;
 
-  const today = new Date();
+  const now = new Date();
 
   const periodsWithInterviewsCurrently = periods.filter((period) => {
-    const interviewStart = new Date(period.interviewPeriod.start);
-    const interviewEnd = new Date(period.interviewPeriod.end);
-    return interviewStart <= today && interviewEnd >= today;
+    const interviewStart = period.interviewPeriod.start;
+    const interviewEnd = period.interviewPeriod.end;
+    return isBeforeOrEqual(interviewStart, now) && isAfterOrEqual(interviewEnd, now);
   });
 
   // Bankom is always active, since you can be a representative of bankom from each committee