diff --git a/package.json b/package.json
index a13c439..3b1c81d 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,6 @@
   "description": "Pokémon Showdown Bot",
   "main": "app.js",
   "dependencies": {
-    "moment": "^2.17.1",
     "mysql": "^2.13.0",
     "node-static": "^0.7.9",
     "sqlite3": "^3.1.8",
diff --git a/plugins/seen.js b/plugins/seen.js
index f401802..1fede7f 100644
--- a/plugins/seen.js
+++ b/plugins/seen.js
@@ -32,7 +32,6 @@ if (!Config.mysql) {
 	});
 }
 
-const moment = require('moment');
 const uuid = require('uuid/v4');
 
 let lastUpdated = {};
@@ -125,7 +124,7 @@ exports.commands = {
 		} else {
 			lastSeen(targetid, data => {
 				if (!data) return this.sendReply(Tools.sanitize(target) + " has never been seen before.");
-				return this.sendReply(Tools.sanitize(data.name) + " was last seen " + data.action + (data.action !== "joining" && data.action !== "leaving" ? " in " : " ") + " **" + data.room + "** on **" + data.server + "** " + moment(data.date).fromNow());
+				return this.sendReply(Tools.sanitize(data.name) + " was last seen " + data.action + (data.action !== "joining" && data.action !== "leaving" ? " in " : " ") + " **" + data.room + "** on **" + data.server + "** " + Tools.toDurationString((Date.now() - data.date), {precision: true}) + " ago");
 			});
 		}
 	},
diff --git a/tools.js b/tools.js
index 90e9d7b..d76c2de 100644
--- a/tools.js
+++ b/tools.js
@@ -8,7 +8,6 @@ let regdateCache = {};
 try {
 	regdateCache = JSON.parse(fs.readFileSync('config/regdate.json', 'utf8'));
 } catch (e) {}
-
 module.exports = {
 	sanitize: function (message) {
 		if (message.charAt(0) === '/') message = '/' + message;
@@ -73,13 +72,21 @@ module.exports = {
 		// https://github.com/tc39/ecma402/issues/47
 		const date = new Date(+number);
 		const parts = [date.getUTCFullYear() - 1970, date.getUTCMonth(), date.getUTCDate() - 1, date.getUTCHours(), date.getUTCMinutes(), date.getUTCSeconds()];
+		const roundingBoundaries = [6, 15, 12, 30, 30];
 		const unitNames = ["second", "minute", "hour", "day", "month", "year"];
 		const positiveIndex = parts.findIndex(elem => elem > 0);
+		const precision = (options && options.precision ? options.precision : parts.length);
 		if (options && options.hhmmss) {
 			let string = parts.slice(positiveIndex).map(value => value < 10 ? "0" + value : "" + value).join(":");
 			return string.length === 2 ? "00:" + string : string;
 		}
-		return parts.slice(positiveIndex).reverse().map((value, index) => value ? value + " " + unitNames[index] + (value > 1 ? "s" : "") : "").reverse().join(" ").trim();
+		// round least significant displayed unit
+		if (positiveIndex + precision < parts.length && precision > 0 && positiveIndex >= 0) {
+			if (parts[positiveIndex + precision] >= roundingBoundaries[positiveIndex + precision - 1]) {
+				parts[positiveIndex + precision - 1]++;
+			}
+		}
+		return parts.slice(positiveIndex).reverse().map((value, index) => value ? value + " " + unitNames[index] + (value > 1 ? "s" : "") : "").reverse().slice(0, precision).join(" ").trim();
 	},
 	// uploadToHastebin function by TalkTakesTime (https://github.com/TalkTakesTime/Pokemon-Showdown-Bot)
 	uploadToHastebin: function (toUpload, callback) {