Type of year E on a solar calendar according to its starting and ending days in the week
A common year starting on Wednesday is any non-leap year (a year with 365 days) that begins on Wednesday, 1 January, and ends on Wednesday, 31 December. Its dominical letter hence is E. The most recent year of such kind was 2014 and the next one will be 2025 in the Gregorian calendar[1] or, likewise, 2015 and 2026 in the obsolete 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 200 when divided by 400. The most recent such year was 1800 and the next one will be 2200.
Any common year that starts on Wednesday has only one Friday the 13th: the only one in this common year occurs in June.
Any common year that starts on Wednesday has two Friday the 17ths: those two in this common year occur in January and October.
Any common year that starts on a Wednesday has only one Tuesday the 13th: the only one in this common year occurs in May.
This is the only type of year in which all dates fall on their respective weekdays 57 times in the 400 year Gregorian Calendar cycle.
In the (currently used) Gregorian calendar, alongside Sunday, Monday, Friday or Saturday, the fourteen types of year (seven common, seven leap) repeat in a 400-year cycle (20871 weeks). Forty-three common years per cycle or exactly 10.75% start on a Wednesday. The 28-year sub-cycle only spans across century years divisible by 400, e.g. 1600, 2000, and 2400.
In the now-obsolete Julian calendar, the fourteen types of year (seven common, seven leap) repeat in a 28-year cycle (1461 weeks). A leap year has two adjoining dominical letters (one for January and February and the other for March to December, as 29 February has no letter). This sequence occurs exactly once within a cycle, and every common letter thrice.
As the Julian calendar repeats after 28 years that means it will also repeat after 700 years, i.e. 25 cycles. The year's position in the cycle is given by the formula ((year + 8) mod 28) + 1). Years 2, 8 and 19 of the cycle are common years beginning on Wednesday. 2017 is year 10 of the cycle. Approximately 10.71% of all years are common years beginning on Wednesday.
