As an airline employee your duty day starts at a specific time. (i.e. 1h20 before a flight)

I want to make a timer app that you can program to start at a specific time. This will help in not having to press a button at a specific time(i.e. forgetting to press or start the timer at a specific time)

I would also like to include a countdown timer that can be set when the flight takes off so knowing the remaining time left on the flight.

Displaying this info in the time zones traveling to and from would be very helpful.  Therefore as the timer countdowns it will show the times in both time zones. 

I'm pretty sure this is way too advanced for this class....any ideas?