Not sure why this was marked as resolved, since EventPrime’s “solution” won’t fix anything. The problem, if they’d bothered to look at the logs provided by the original reporter, is the time picker format they’ve specified in the admin scripts isn’t recognised by the timepicker jQuery plugin they’re using. It’s saving the time as “{hour}:i A” which then can’t be parsed by the DateTime constructor (and they’ve done no validation/error handling on the date parsing, which is just reckless).
If you want to fix it yourself you need to edit {plugin path}/admin/js/em-admin-metabox-custom.js and replace all instances of “h:i A” with “h:mm TT”
