I wish there were a way to award best answer to both David Hartley and George Fulton...
I presume both calculators linked to will give the date in the Gregorian calendar. Is it true that if one region uses the Gregorian calendar and another uses the Julian calendar, then the Easter dates in both places will coincide if both are converted to the same calendar? (It seems true, but I haven't had enough coffee yet to reason it out.)