How to setup birthdate field with optional values I want to have a "birthdate" field for my users. It should be optional to enter a year or a date.
If a year is selected I want to display the age. If a date is entered I want to show the birthdate.

If I use the date field and make it optional I can have empty default values. However, as soon as I enter a year it requires the date and month too and vise versa.

Any solutions?
I would define 3 optional selects:
 - Year (now() to now() - 100)
 - Month (1-12)
 - Day (1-31)   

Then in a hook_node_validate() I would check if only the year is provided or a full date. Also don't forget to verify if the date is valid (like Feb, 31...) using checkdate( int $month , int $day , int $year ).

Then create a field template to either display the age or a birthdate.