fix: address bot review feedback for time-range support

- Fix statsPeriod/start+end conflict: API functions with fallback
  statsPeriod defaults now guard with start/end presence check
- Fix normalizeDateOnly day arithmetic: use local setDate/setHours
  instead of UTC round-trip to prevent date shift in extreme timezones
- Reject all absolute ranges with --follow, not just end-bounded

Author: BYK

src/commands/log/list.ts

@@ -689,12 +689,12 @@ export const listCommand = buildListCommand(
           : DEFAULT_PROJECT_PERIOD);
       const timeRange = parsePeriod(effectivePeriod);
 
-      // Follow mode cannot be used with an end-bounded absolute range —
-      // streaming polls for new events, but an end date caps the window.
-      if (flags.follow && timeRange.type === "absolute" && timeRange.end) {
+      // Follow mode streams live events via short polling intervals —
+      // absolute date ranges are silently ignored, so reject them entirely.
+      if (flags.follow && timeRange.type === "absolute") {
         throw new ValidationError(
-          "--follow cannot be used with an end date boundary. " +
-            "Remove the end date to stream new events.",
+          "--follow cannot be used with an absolute date range. " +
+            "Use a relative duration (e.g., --period 1h) or omit --period.",
           "period"
         );
       }

src/lib/api/logs.ts

@@ -101,7 +101,10 @@ export async function listLogs(
       project: isNumericProject ? [Number(projectSlug)] : undefined,
       query: fullQuery || undefined,
       per_page: options.limit || API_MAX_PER_PAGE,
-      statsPeriod: options.statsPeriod ?? "30d",
+      statsPeriod:
+        options.start || options.end
+          ? undefined
+          : (options.statsPeriod ?? "30d"),
       start: options.start,
       end: options.end,
       sort: toApiSort(options.sort),
@@ -250,7 +253,10 @@ export async function listTraceLogs(
     {
       params: {
         traceId,
-        statsPeriod: options.statsPeriod ?? "14d",
+        statsPeriod:
+          options.start || options.end
+            ? undefined
+            : (options.statsPeriod ?? "14d"),
         start: options.start,
         end: options.end,
         per_page: options.limit ?? API_MAX_PER_PAGE,

src/lib/api/traces.ts

@@ -235,7 +235,10 @@ export async function listTransactions(
           // omitting the parameter.
           query: fullQuery || undefined,
           per_page: options.limit || 10,
-          statsPeriod: options.statsPeriod ?? "7d",
+          statsPeriod:
+            options.start || options.end
+              ? undefined
+              : (options.statsPeriod ?? "7d"),
           start: options.start,
           end: options.end,
           sort:
@@ -323,7 +326,10 @@ export async function listSpans(
         project: isNumericProject ? projectSlug : undefined,
         query: fullQuery || undefined,
         per_page: options.limit || 10,
-        statsPeriod: options.statsPeriod ?? "7d",
+        statsPeriod:
+          options.start || options.end
+            ? undefined
+            : (options.statsPeriod ?? "7d"),
         start: options.start,
         end: options.end,
         sort: options.sort === "duration" ? "-span.duration" : "-timestamp",

src/lib/time-range.ts

@@ -147,6 +147,9 @@ export function parseDate(raw: string, position: DatePosition): string {
  *
  * Constructs datetimes without "Z" so `new Date()` interprets them as local time,
  * then converts to UTC via `.toISOString()`.
+ *
+ * Day arithmetic for "after"/"before" uses local Date methods (setDate/setHours)
+ * to avoid UTC/local mismatches in extreme timezones.
  */
 function normalizeDateOnly(dateStr: string, position: DatePosition): string {
   // Validate the date is parseable
@@ -159,17 +162,18 @@ function normalizeDateOnly(dateStr: string, position: DatePosition): string {
     return new Date(`${dateStr}T23:59:59.999`).toISOString();
   }
   if (position === "after") {
-    // Exclusive start (>): next day's local midnight
-    const nextDay = new Date(`${dateStr}T12:00:00`);
-    nextDay.setDate(nextDay.getDate() + 1);
-    const nextStr = nextDay.toISOString().slice(0, 10);
-    return new Date(`${nextStr}T00:00:00`).toISOString();
+    // Exclusive start (>): next day's local midnight.
+    // Use local Date methods throughout to avoid UTC/local day mismatch.
+    const d = new Date(`${dateStr}T00:00:00`);
+    d.setDate(d.getDate() + 1);
+    d.setHours(0, 0, 0, 0);
+    return d.toISOString();
   }
-  // position === "before": Exclusive end (<): previous day's local end-of-day
-  const prevDay = new Date(`${dateStr}T12:00:00`);
-  prevDay.setDate(prevDay.getDate() - 1);
-  const prevStr = prevDay.toISOString().slice(0, 10);
-  return new Date(`${prevStr}T23:59:59.999`).toISOString();
+  // position === "before": Exclusive end (<): previous day's local end-of-day.
+  const d = new Date(`${dateStr}T23:59:59.999`);
+  d.setDate(d.getDate() - 1);
+  d.setHours(23, 59, 59, 999);
+  return d.toISOString();
 }
 
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