How can I coordinate multiple attacks so that they all hit at the same time?

Question

I am playing a game (Valor on iPad) and several people are attacking a single city. We're all different distances away and have various troops that have different travel times. We need to be able to pick a time for us to hit the city, then count back the travel durations to determine what time we need to kick off each unit's attack.

Yes, I can do this on paper, but there are so many units and so many starting cities that it'd be great if someone could show me how to use Excel or something to do the computations.

Answer 1

Using variables in some kind of programming language would be the easiest, I think. I would just have a travel time variable for each location, and then a variable for each unit's travel time. Then just multiply the amount of each unit by that unit's travel time variable, then add or multiply that by the location travel time variable, depending on how the game works.

You could just do it on paper though, it might just take longer.