The unix timestamp is a number representing the number of seconds since 1970. Most applications use this value to keep track of what time it is. If you have a unix timestamp and need to see what time it represents, you can create a basic php script to decode it for you. Create a time.php in your public_html foler, and enter the following data:
echo date("r", $_GET['time']);
<form action=time.php method=GET name=form>
Timestamp: <input type=text name=time> <input type=submit>
Then view it through the web, enter the number and submit the form.