From 64b98caac916d13bd80356306a39699181784788 Mon Sep 17 00:00:00 2001
From: "claude[bot]" <209825114+claude[bot]@users.noreply.github.com>
Date: Thu, 16 Jul 2026 07:13:12 +0000
Subject: [PATCH] fix: cap year at 4 digits and prevent crash on invalid
 datetime input
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- Add max="9999-12-31[T23:59]" to datetime-local inputs so years cannot
  exceed 4 digits.
- Drop the redundant `format(localValue, formatStr)` call in the render
  path — `localValue` is already the formatted string from the effect,
  and re-formatting a raw user string with an out-of-range year threw
  `RangeError: Invalid time value` mid-render, which the global error
  boundary caught as a page crash.

Fixes #3640

Co-authored-by: aseckin <3686968+aseckin@users.noreply.github.com>
---
 front_end/src/components/ui/datetime_utc.tsx | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/front_end/src/components/ui/datetime_utc.tsx b/front_end/src/components/ui/datetime_utc.tsx
index bfca108e5e..7fce4f16c2 100644
--- a/front_end/src/components/ui/datetime_utc.tsx
+++ b/front_end/src/components/ui/datetime_utc.tsx
@@ -83,7 +83,8 @@ const DatetimeUtc = forwardRef<HTMLInputElement, DatetimeUtcProps>(
       <Input
         ref={ref}
         type="datetime-local"
-        defaultValue={localValue ? format(localValue, formatStr) : ""}
+        defaultValue={localValue}
+        max={props.type === "date" ? "9999-12-31" : "9999-12-31T23:59"}
         className={className}
         onChange={handleChange}
         onBlur={handleChange}