Pattern With A Twist

[nofue]

Given a Time field with a pattern of [0-2][0-9][:-][0-5][0-9] doesn't work while empty. Only when a value is set for the form field, the pattern works, and it works particularly well, but as long as you deal with an empty field, it doesn't look like that.
Just saying …

[lovasoa]

No, that's not how patterns work. The browser does allow you to leave the field blank as long at it's not marked "required":

Screencast.From.2025-10-06.17-34-57.mp4

But use 'time' as type instead

You can also use a native time selection field, where the format will respect the user's locale time display preferences

select 'form' as component;
select 'time' as name, 'time' as type;

Screencast.From.2025-10-06.17-37-29.mp4

[nofue]

You didn't get it.I didn't sayvpattern should work as a subsitute for required. What I said was, that the pattern isn't enforced when the field is empty in the beginning. I.e. when I set the pattern to match hours and minutes, I could enter almost every nonsense and only when leaving the field a message was thrown. Once I set a value, the pattern was enforced as I typed.

However, setting 'time' as type makes sense -- I wonder why it's missing from my source -- thanks for the hint.

[lovasoa]

Indeed I had misunderstood what you meant. Yes, browsers warn about invalid form fields at submission time, not at input time.