This would be very complicated to do; I don't think a seconds field is standard in web browsers for a time input. Would also require major API refactoring.
Re-opening because I think this is an issue considerable enough that we need to come up with a solution. It is not practical and very unfriendly to have forum posts changing order when this happens.
Suggestion: Add / attach seconds as a hidden value on the edit screen. Maintain the seconds value on save (even if the minutes / hours are changed). Do this on all time fields, and make sure getting dates from post/get params also looks for this special hidden value.
Suggestion: Add / attach seconds as a hidden value on the edit screen. Maintain the seconds value on save (even if the minutes / hours are changed). Do this on all time fields, and make sure getting dates from post/get params also looks for this special hidden value.