Dear Experts

I want to display Sun Position with progress bar, I mean how much time is left to sun set.

Explanation:
Sun rises on=05:13
Sun sits on=07:18
Current time=03:44

Now we convert time in seconds

Sun rises on=18780
Sun sits on=69480
Current time=56668

Day left?
69480-56668=12812

Progress bar first value is=56668
Progress bar first value is=69480

How to display 12812 portion on progress bar?

How to devide values for progress bar?

Please help