From f4d7c86ec0d5fbcd951b1b241ae36d168e71e9ea Mon Sep 17 00:00:00 2001
From: jojo <49631805+joj0hq@users.noreply.github.com>
Date: Mon, 27 Jul 2026 16:31:45 +1000
Subject: [PATCH] fix(ui): parse naive-UTC timestamps consistently in
 formatAbsoluteDate (#953)
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* fix(ui): parse naive-UTC timestamps consistently in formatAbsoluteDate

Backend timestamps are naive UTC (Python `datetime.utcnow()`) and are
serialized without a timezone suffix. `formatDate` already normalizes
these by appending `Z` before parsing, but `formatAbsoluteDate` called
`new Date(date)` directly. Per the ES spec, a timezone-less date-time
string is parsed as local time, so absolute timestamps were shown off by
the viewer's UTC offset (e.g. +9h in JST) — and disagreed with the
relative time rendered by `formatDate` for the same value (visible in the
Captures detail panel, which uses both on `capture.created_at`).

Extract the normalization into a shared `parseServerDate` helper and use
it in both formatters.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* docs(format): clarify parseServerDate comment on date-only vs date-time parsing

ECMAScript parses date-only strings ("2026-07-23") as UTC but timezone-less
date-time strings ("2026-07-23T10:00:00") as local time. The backend emits the
latter, which is the case this helper normalizes. Corrects the comment per PR
review feedback.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

* docs(format): trim parseServerDate comment to match surrounding style

Reduce the multi-line explanation to a single why-comment consistent with
other utils comments.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 app/src/lib/utils/format.ts | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/app/src/lib/utils/format.ts b/app/src/lib/utils/format.ts
index 0d01a7fd..74aaa7d3 100644
--- a/app/src/lib/utils/format.ts
+++ b/app/src/lib/utils/format.ts
@@ -23,27 +23,28 @@ function getDateLocale() {
   }
 }
 
-export function formatDate(date: string | Date): string {
-  let dateObj: Date;
-  if (typeof date === 'string') {
-    const dateStr = date.trim();
-    if (!dateStr.includes('Z') && !dateStr.match(/[+-]\d{2}:\d{2}$/)) {
-      dateObj = new Date(`${dateStr}Z`);
-    } else {
-      dateObj = new Date(dateStr);
-    }
-  } else {
-    dateObj = date;
+// Backend timestamps are naive UTC — append `Z` so JS doesn't parse a
+// timezone-less date-time string as local time.
+function parseServerDate(date: string | Date): Date {
+  if (typeof date !== 'string') {
+    return date;
   }
+  const dateStr = date.trim();
+  if (!dateStr.includes('Z') && !dateStr.match(/[+-]\d{2}:\d{2}$/)) {
+    return new Date(`${dateStr}Z`);
+  }
+  return new Date(dateStr);
+}
 
-  return formatDistance(dateObj, new Date(), {
+export function formatDate(date: string | Date): string {
+  return formatDistance(parseServerDate(date), new Date(), {
     addSuffix: true,
     locale: getDateLocale(),
   }).replace(/^about /i, '');
 }
 
 export function formatAbsoluteDate(date: string | Date): string {
-  const dateObj = typeof date === 'string' ? new Date(date) : date;
+  const dateObj = parseServerDate(date);
   return dateObj.toLocaleString(i18n.language, {
     month: 'short',
     day: 'numeric',