Countdown timer

I have a countdown timer that will always count doen between 6 am today and 6 am tomorrow. I am trying to follow alomg with this thread on DMXZone website, but not having any luck:

DMX Thread

is it better to do whole calc on backend and then send hours, minutes and seconds back or just format on front end.

To sum up I need hours, minutes and seconds from now to time I have in db.

Please help