Convert Date to Timestamp.

[Sara]

I am getting Month, Day and Year from Drop Downs of a form to convert given 
values to Unix timestamp.
I am able to put values in all the variables below except for $wday & $yday. 
Any ideas as how I can get those with limited user input of month, day and year 
only?

#!/usr/local/bin/perl
use POSIX;

$sec = 1;
$min = 0;
$hour = 0;
$mday = 01;
$mon = 10;
$year = 107;
$wday = ?;
$yday = ?;
$timestamp = mktime($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,-1);
print ($timestamp);