A common year starting on Thursday is any non-leap year (i.e. a year with 365 days) that begins on Thursday, 1 January, and ends on Thursday, 31 December. Its dominical letter hence is D. The current year, 2026, is a common year starting on Thursday in the Gregorian calendar, and the next such year will be 2037, or, likewise, 2021 and 2027 in...