Before/After Time from UI not encoding properly

[tobybaratta]

Description:

When making a request through the Search Posts UI, the request is being sent without the properly encoded times and thus querying for what seems to be the lifetime of a subreddit.

Repro:

1. Open the search UI.
2. Type in the "UmamusumeGame" subreddit and the title word search of "whale".
3. Use the UI to select a before and after date of Aug 1 - Sept 30. Set the times as midnight for both. Keep limit as "10".
4. See a timeout message. The network console is showing 422 and a URL encoding with the date/time formatted like: 2025-08-01T00:00.
5. Open network console and do the "edit and resend" option.
6. Send with times formatted like: 2025-08-01T00:00:00Z for both dates.
7. See that it returns a JSON of 9 posts with no issue.

If you don't set any time value, it sometimes seems to work properly and not timeout, but you have to manually clear the URL bar to get it to not keep the time values. I'm not super sure what's going on with it, but find it super strange what it likes and what it doesn't like, but that it definitely doesn't like the default style of encoding where it's seemingly not parsing AM or PM right, or missing milliseconds?

Thank you!