Sounds like you have some other plugin that is loading a script globally on the admin side that is applying something to inputs with the “timepicker” class that is overriding the way the timepicker script I’m using is trying to format those times.
When validating, my plugin expects the time to be in the format:
XX:XX YY
needs to see two digits for hour and minutes, a space, and then AM or PM (can also be am or pm). So 1:30pm should actually be 01:30 PM.
Some other plugins’ script is changing that on your system, so it’s not passing validation. I assure you it’s working just fine here, and nobody else in the over 2000 active installs have reported any similar issues.
That timepicker script that I use is a jquery ui plugin from another developer, and the version I have in my plugin is the latest version (it’s simple and has not been updated for a long time).
You’ll have to figure out what other plugins, or possibly even your theme, are using some similar type of timepicker script on their admin pages to figure out where the conflict is.
Not much I can do about it unless I rewrite my plugin’s code that displays that form, along with the corresponding javascript, and change my class names to something that hopefully nobody else is using globally. Better solution would be to have the other plugin (or theme) only queue up that script on its own pages instead of globally (although, I’m guilty of doing that myself in some of these plugins… it’s a common thing).