I need a stopwatch (visible to users) to store the time that a user was logged into my site. And I need this information being stored in database.
Example: A user connects now and stays for 10 minutes. In another time (maybe another day) it connects again and stays for 15 minutes. I need to store the total time: 25 minutes.
I need that there is no interference related to time zone or something. The meter needs to be precise.
I thought about jQuery + PHP + MySQL, but I'm open to suggestions. Just need to use PHP.