This year, Western Christians and Greek Orthodox believers — who use different liturgical calendars — celebrate Easter, or Pascha one week apart, with the former being on April 17 and the latter April 24.
In 2017, Easter came at the same time for both denominations, something that will happen again in 2025.
However, for purely astronomical reasons, the difference between the celebration of Easter for the two denominations will be getting wider by quite a few years.
And from 2700 and onward, the celebration of Easter for the Greek Orthodox Church and the western Christian churches will never coincide again.
Altogether, in the whole 21st century, the celebration of Easter will be held common 31 years, but during every forthcoming century this will happen more and more rarely.