Date

Hi! can someone please tell me how to get the current date? Well, the thing is, i want to manage a subscription, so, in my database, i have a field called date_registered which will be assigned to the date that any user registers... so, i have to capture that date value which can vary depending on when a user registers. So, let's say $date1 will be assigned to that value. Now, how can i perform addition with the date so that i mail that user 3 months after the date he registered that his registration has expired? Therefore, i'll be having 2 dates $date1 = "the date the user registers"; $date2 = $date1 + 3months can someone please help me with that? Thanks and regards, Yogesh Mahadnac