Hi,
u should try to use sessions.Its really simple.
at the top of every page,put:
<?php
session_start();
?>
the page where u input date,put(for example)
<?
$date = $_POST[date];
$_SESSION['date']= $date;
?>
and for the rest of the page where u want to use date,just simply retrieve it
<?
$date = $_SESSION['date'];
//to use
echo $date;
hope it helps.. 🙂