MST means Mountain Standard time while EST means Eastern Standard time.
MST is 2 hours behind EST.
This means that if it is 5:00 + 2 hours = 7:00 would be the time in EST.
So if we depart 3:30 am MST this means that we departed at 5:30 am in EST.
So, 12 hours and 10 mins would be the travel time.