common year starting and ending on Monday

A common year starting on Monday is any non-leap year (i.e., a year with 365 days) that begins on Monday, 1 January, and ends on Monday, 31 December. Its dominical letter hence is G. The most recent year of such kind was 2018, and the next one will be 2029 in the Gregorian calendar, or likewise, 2019 and 2030 in the Julian calendar, see below for more. This common year is one of the three possible common years in which a century year can begin on and occurs in century years that yield a remainder of 300 when divided by 400. The most recent such year was 1900, and the next one will be 2300.

Any common year that starts on Monday has two Friday the 13ths: those two in this common year occur in April and July. Leap years starting on Sunday share this characteristic, but also have another in January. From July of the year in this type of year to September in the year that follows this type of year is the longest period that occurs without a Friday the 13th and this happens 29 out of the 43 common year starting on Monday and happens in years (e.g. 2018-2019 and 2029-2030), unless the following year is a leap year starting on Tuesday, in which case the gap is only 11 months, as the next Friday the 13th is already in June. This happens 14 out of 43 common year starting on Monday and this happens in years (e.g. 2007-2008 and 2035-2036).