Is it possible to make date of birth private?

When people join my community, is there a way to not display their age in their profile while keepingh a restriction on minimum age, and can I add a message next to the field to say that their age will not be displayed?

Yes, several places.

Look in the Builders, Profile Fields, drag out what you don't want.

Admin Controls block is only of course seen by the Admin. Not members.

Under Settings, Advanced Settings, look for Member Brief Info: Age + Sex... 

To add "extra text" to form or site, that is under the Language section and keys.

If your not familial with that using the site search here will help a lot.

Many thanks, newton27. Now I know where to look. :0)

 Your welcome