Common year starting on Friday
A common year starting on Friday is any non-leap year (i.e. a year with 365 days) that begins on Friday, 1 January, and ends on Friday, 31 December. Its dominical letter hence is C. The most recent year of such kind was 2021 and the next one will be 2027 in the Gregorian calendar,[1] or, likewise, 2011, 2022 and 2033 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 100 when divided by 400. The most recent such year was 1700 and the next one will be 2100.
Any common year that starts on Wednesday, Friday or Saturday has only one Friday the 13th: the only one in this common year occurs in August. Leap years starting on Thursday share this characteristic, but also have another one in February.
From July of the year that precedes this year until September in this type of year is the longest period (14 months) that occurs without a Friday the 17th. Leap years starting on Tuesday share this characteristic, from August of the common year that precedes it to October in that type of year.
Calendars
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| ISO 8601-conformant calendar with week numbers for any common year starting on Friday (dominical letter C) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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This is the only year type where the nth "Doomsday" (this year Sunday) is not in ISO week n; it is in ISO week n-1.
Applicable years
Gregorian calendar
In the (currently used) Gregorian calendar, alongside Sunday, Monday, Wednesday 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 Friday. The 28-year sub-cycle only spans across century years divisible by 400, e.g. 1600, 2000, and 2400.
| Decade | 1st | 2nd | 3rd | 4th | 5th | 6th | 7th | 8th | 9th | 10th | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 16th century | prior to first adoption (proleptic) | 1593 | 1599 | ||||||||||||
| 17th century | 1610 | — | 1621 | 1627 | 1638 | 1649 | 1655 | 1666 | 1677 | 1683 | 1694 | 1700 | |||
| 18th century | 1706 | 1717 | 1723 | 1734 | 1745 | 1751 | 1762 | 1773 | 1779 | 1790 | — | ||||
| 19th century | 1802 | 1813 | 1819 | 1830 | — | 1841 | 1847 | 1858 | 1869 | 1875 | 1886 | 1897 | |||
| 20th century | 1909 | 1915 | 1926 | 1937 | 1943 | 1954 | 1965 | 1971 | 1982 | 1993 | 1999 | ||||
| 21st century | 2010 | — | 2021 | 2027 | 2038 | 2049 | 2055 | 2066 | 2077 | 2083 | 2094 | 2100 | |||
| 22nd century | 2106 | 2117 | 2123 | 2134 | 2145 | 2151 | 2162 | 2173 | 2179 | 2190 | — | ||||
| 23rd century | 2202 | 2213 | 2219 | 2230 | — | 2241 | 2247 | 2258 | 2269 | 2275 | 2286 | 2297 | |||
| 24th century | 2309 | 2315 | 2326 | 2337 | 2343 | 2354 | 2365 | 2371 | 2382 | 2393 | 2399 | ||||
400 year cycle:
- century 1: 010, 021, 027, 038, 049, 055, 066, 077, 083, 094, 100
- century 2: 106, 117, 123, 134, 145, 151, 162, 173, 179, 190
- century 3: 202, 213, 219, 230, 241, 247, 258, 269, 275, 286, 297
- century 4: 309, 315, 326, 337, 343, 354, 365, 371, 382, 393, 399
Julian calendar
In the now-obsolete Julian calendar, the fourteen types of year (seven common, seven leap) repeat in a 28-year cycle (1461 weeks). 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 4, 15 and 26 of the cycle are common years beginning on Friday. 2017 is year 10 of the cycle. Approximately 10.71% of all years are common years beginning on Friday.
| Decade | 1st | 2nd | 3rd | 4th | 5th | 6th | 7th | 8th | 9th | 10th | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 15th century | 1406 | 1417 | 1423 | 1434 | 1445 | 1451 | 1462 | 1473 | 1479 | 1490 | — | |||||||||
| 16th century | 1501 | 1507 | 1518 | 1529 | 1535 | 1546 | 1557 | 1563 | 1574 | 1585 | 1591 | |||||||||
| 17th century | 1602 | 1613 | 1619 | 1630 | — | 1641 | 1647 | 1658 | 1669 | 1675 | 1686 | 1697 | ||||||||
| 18th century | 1703 | 1714 | 1725 | 1731 | 1742 | 1753 | 1759 | 1770 | — | 1781 | 1787 | 1798 | ||||||||
| 19th century | 1809 | 1815 | 1826 | 1837 | 1843 | 1854 | 1865 | 1871 | 1882 | 1893 | 1899 | |||||||||
| 20th century | 1910 | — | 1921 | 1927 | 1938 | 1949 | 1955 | 1966 | 1977 | 1983 | 1994 | |||||||||
| 21st century | 2005 | 2011 | 2022 | 2033 | 2039 | 2050 | — | 2061 | 2067 | 2078 | 2089 | 2095 | ||||||||
Holidays
International
- Valentine's Day falls on a Sunday
- World Day for Grandparents and the Elderly falls on July 25
- Halloween falls on a Sunday
- Christmas Day falls on a Saturday
Roman Catholic Solemnities
- Epiphany falls on a Wednesday
- Candlemas falls on a Tuesday
- Saint Joseph's Day falls on a Friday
- The Annunciation of Jesus falls on a Thursday
- The Nativity of John the Baptist falls on a Thursday
- The Solemnity of Saints Peter and Paul falls on a Tuesday
- The Transfiguration of Jesus falls on a Friday
- The Assumption of Mary falls on a Sunday
- The Exaltation of the Holy Cross falls on a Tuesday
- All Saints' Day falls on a Monday
- All Souls' Day falls on a Tuesday
- The Feast of Christ the King falls on November 21 (or on its latest possible date of October 31 in versions of the calendar between 1925 and 1962)
- The First Sunday of Advent falls on November 28
- The Immaculate Conception falls on a Wednesday
- Gaudete Sunday falls on December 12
- Rorate Sunday falls on December 19
Australia and New Zealand
- Australia Day falls on a Tuesday
- Waitangi Day falls on a Saturday
- Daylight saving ends on April 4
- ANZAC Day falls on a Sunday, and in some years coincides with Easter Sunday falling on its latest possible date
- Mother's Day falls on May 9
- Father's Day falls on September 5
- Daylight saving begins on September 26 in New Zealand and October 3 in Australia
British Isles
- Saint David's Day falls on a Monday
- Mother's Day falls on March 7, March 14, March 21, March 28 or on its latest possible date of April 4
- Daylight saving begins on March 28
- Saint Patrick's Day falls on a Wednesday
- Saint George's Day falls on a Friday, and in some years coincides with Good Friday falling on its latest possible date
- Father's Day falls on June 20
- Orangeman's Day falls on a Monday
- Daylight saving ends on its latest possible date, October 31
- Guy Fawkes Night falls on a Friday
- Saint Andrew's Day falls on a Tuesday
Canada
- Daylight saving begins on its latest possible date, March 14
- Mother's Day falls on May 9
- Victoria Day falls on its latest possible date, May 24
- Father's Day falls on June 20
- Canada Day falls on a Thursday
- Labour Day falls on September 6
- Thanksgiving Day falls on October 11
- Daylight saving ends on its latest possible date, November 7
United States
- Martin Luther King Jr. Day falls on January 18
- President's Day falls on its earliest possible date, February 15
- Daylight saving begins on its latest possible date, March 14
- Mother's Day falls on May 9
- Memorial Day falls on its latest possible date, May 31
- Juneteenth falls on a Saturday
- Father's Day falls on June 20
- Independence Day falls on a Sunday
- Labor Day falls on September 6
- Grandparents' Day falls on September 12
- Columbus Day falls on October 11
- Daylight saving ends on its latest possible date, November 7
- Thanksgiving Day falls on November 25
References
- Robert van Gent (2017). "The Mathematics of the ISO 8601 Calendar". Utrecht University, Department of Mathematics. Retrieved 20 July 2017.