If you reuse old calendars, those from 2015, 2009, 1998, 1987 and 1981 will work for 2026, though the dates for Easter will probably be wrong. Those from 2020 and 1992 will work from March on.
Trivia that matter
If you reuse old calendars, those from 2015, 2009, 1998, 1987 and 1981 will work for 2026, though the dates for Easter will probably be wrong. Those from 2020 and 1992 will work from March on.