??Code to convert input time and date to epoch time??

Using Arduino Programming Questions
#1

Anyone know how to convert a time and date inputed by a user to epoch time?? (seconds since midnight Jan 1 1970)
that would be functional with arduino?

#2

This should help:

http://www.arduino.cc/playground/Code/Time

now();             // returns the current time as seconds since Jan 1 1970
#3