Year of birthday in desc order

Hi, i have a birthday field.

I would like that when the user select the year this appear in desc order.

Now, it appear in this order.
1900
1901
1902
...
1994

it is a huge dropdown, when the most of the users are below 50 years.

it would prefer that appear as this:
1994
1993
...
1900

i am looking file cb.core.php but dont find how change it.

Thanks.

There's no parameter for this so you'd need to edit cb.core.php and adjust the order that it adds dates. We do not support core edits so we can not help you with this, sorry.