D.O.B. info...

I’ve seen various listings that do not have a birthday posted next to the actor’s name.  While I don’t have a problem with disclosing my age in the least to whoever might want to know, I’ve also been told that I don’t look my age and would prefer to keep that data point opened ended for the purpose of potential future work.  As such, how can I get the d.o.b. listing removed from my imdb page?

Thanks in advance for any help in this area.