I've got a content type with two date fields in it. Both fields prompt for year, month, day, hour, minute.

I recently learned for this site, the two date fields will always have the same day (i.e. year, month, and day). So, I'm trying to simplify the form. I'd like the second date field to prompt only for the hour and minutes.

I'm confortable with form_alters and after_builds and all that jazz. But what date.module is building I just can't seem to modify successfully.

For example, I've added an #after_build to my date element, via hook_form_alter(). In my after_build callback, I've tried a few things. I've added ['#access'] = FALSE to the 'month', 'day' and 'year' parts of the widget. When I do so I get an error about the date being invalid.

I've tried ['#type'] = 'hidden' instead of ['#access']=FALSE, but got the same error.

I've tried changing those month, day and year elements to array('#type' => value, '#value' => $reasonable_default); Again, same validation error.

I'm wondering, is it possible to alter the date widget in this sort of way?

BTW, I'm aware I can configure a field to prompt for different portions of a date, but only when there is not existing data. I can't change that for an existing field. Thanks for any help.