need help calculating time in javascript.

[#1]

Dear Adobe

I require assistance on a script to calculate a new time of a field. 

This is a navigation form that requires the user to insert a departure time in minutes, then add more time to that in aseparate field and show the result in the next field.

i.e.

Departing at 10:00 (field1)

Time to next waypoint = 78 miutes 

Passing next waypoint = 11:18  (field3)

I need to calculate field3 and display like that, preferably with AM/PM if possible.

Any advice would be appreciated, thanks.

[#2]

Dear Adobe

I require assistance on a script to calculate a new time of a field. 

This is a navigation form that requires the user to insert a departure time in minutes, then add more time to that in aseparate field and show the result in the next field.

i.e.

Departing at 10:00 (field1)

Time to next waypoint = 78 miutes 

Passing next waypoint = 11:18  (field3)

I need to calculate field3 and display like that, preferably with AM/PM if possible.

Any advice would be appreciated, thanks.

[#3]

Working with date/time in Acrobat JavaScript is not trivial. You should start by reading these tutorials:

https://acrobatusers.com/tutorials/working-with-date-and-time-in-acrobat-javascript
https://acrobatusers.com/tutorials/working-with-date-and-time-in-acrobat-javascript-part-2
https://acrobatusers.com/tutorials/working-date-and-time-acrobat-javascript-part-3-3