Batch update via profile on Date input field

When batch updating a field with input type "Date" (that includes time as well), any times that have already been entered into records get "zeroed" — they get changed to 12:00AM.

I recreated this bug in sandbox.civicrm.org for the event called Test Batch Update Time Event. I added a custom data group called Event Participant Travel Info, and tried to update Participant Arrival Information via profile.

Where I had already entered times for participants, the values went to 12:00AM. Where I hadn't, they were blank as expected. The problem is where values have already been entered because unless you hit cancel during the update, all the data you've entered gets lost every time you try the batch update.

Hope this is clear — let me know if I can give more info.

Robyn
Progressive Technology Project