In closed psychiatric clinics, yes! 
You seem to know well and to be quite familiar with what happens inside a psychiatric clinic !
So if you are born September 3rd and someone asks for your birthday you will say that you are born around July!!!
Yes.
If I am born on the 3rd September 1975 and my girlfriend is born on the 15th of July 1975, we are born around the same date !
Do you need any more english words explained to you ?!