A function that will calculate total days from a date. Take a look at getdate() function to understand better.

The name says it all. You can find the age of the person by his birthday. The idea was not mine , I have seen something like this in another language and thought It would be nice to make it in php. Example on how to use :

Just a simple login system..i used to have it in my site now i think it might be usefull for anyone who needs a login system.. Feel free to modify.