did you look at the manual for mktime? It has six parameters...
mktime(hour,minute,second,day,month,year)
So, use current values for day and year, but add 3 to month...
$new_date = date("Y-m-d H:i:s",mktime(0,0,0,date("d"),date("m")+3,date("Y")));
I think that'll work.
You never answered if this has anything to do with MySQL...
---John Holmes...