I have a smartdate field that allows time input. When you hover over the field some help text appears (the title attribute). But the problem is that because it's a time field, we don't actually know what format the browser is going to use, based on the locale of the browser.
Core has recently removed similar help text because of this problem. I suppose that it might be possible to do something fancy to determine the format that the browser is going to use, but that sounds like a lot of work for little gain.
Closed: works as designed
4.1
Code