Editing Common year starting on Sunday (section)

== Applicable years ==

=== Gregorian Calendar ===
In the (currently used) Gregorian calendar, alongside [[Common year starting on Monday|Monday]], [[Common year starting on Wednesday|Wednesday]], [[Common year starting on Friday|Friday]] or [[Common year starting on Saturday|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 Sunday. The 28-year sub-cycle only spans across century years divisible by 400, e.g. 1600, 2000, and 2400.

{| class="wikitable"
|+ Gregorian common years starting on Sunday<ref name="math"/>
!scope=row| Century
! 1st !!colspan=2| 2nd !! 3rd !!colspan=2| 4th !!colspan=2| 5th !! 6th !!colspan=2| 7th !!colspan=2| 8th !! 9th !!colspan=2| 10th
|- style="opacity: 0.5;"
! style="background-color:#efefef;" | [[16th century]]
|colspan=13| ''prior to first adoption (proleptic)'' || [[1589]] ||colspan=2| [[1595]]
|- style="opacity: 0.5;"
! style="background-color:#efefef;" | [[17th century]]
| [[1606]] ||colspan=2| [[1617]] || [[1623]] ||colspan=2| [[1634]] ||colspan=2| [[1645]] || [[1651]] ||colspan=2| [[1662]] || [[1673]] || [[1679]] || — ||colspan=2| [[1690]]
|-
! style="background-color:#efefef;" | [[18th century]]
| [[1702]] || [[1713]] || [[1719]] || — ||colspan=2| [[1730]] || [[1741]] || [[1747]] || [[1758]] ||colspan=2| [[1769]] ||colspan=2| [[1775]] || [[1786]] ||colspan=2| [[1797]]
|-
! style="background-color:#efefef;" | [[19th century]]
| [[1809]] ||colspan=2| [[1815]] || [[1826]] ||colspan=2| [[1837]] ||colspan=2| [[1843]] || [[1854]] ||colspan=2| [[1865]] ||colspan=2| [[1871]] || [[1882]] || [[1893]] || [[1899]]
|-
! style="background-color:#efefef;" | [[20th century]]
| [[1905]] ||colspan=2| [[1911]] || [[1922]] || [[1933]] || [[1939]] ||colspan=2| — || [[1950]] || [[1961]] || [[1967]] ||colspan=2| [[1978]] || [[1989]] ||colspan=2| [[1995]]
|-
! style="background-color:#efefef;" | [[21st century]]
| [[2006]] ||colspan=2| [[2017]] || [[2023]] ||colspan=2| [[2034]] ||colspan=2| [[2045]] || [[2051]] ||colspan=2| [[2062]] || [[2073]] || [[2079]] || — ||colspan=2| [[2090]]
|-
! style="background-color:#efefef;" | [[22nd century]]
| [[2102]] || [[2113]] || [[2119]] || — ||colspan=2| [[2130]] || [[2141]] || [[2147]] || [[2158]] ||colspan=2| [[2169]] ||colspan=2| [[2175]] || [[2186]] ||colspan=2| [[2197]]
|-
! style="background-color:#efefef;" | [[23rd century]]
| [[2209]] ||colspan=2| [[2215]] || [[2226]] ||colspan=2| [[2237]] ||colspan=2| [[2243]] || [[2254]] ||colspan=2| [[2265]] ||colspan=2| [[2271]] || [[2282]] || [[2293]] || [[2299]]
|-
! style="background-color:#efefef;" | [[24th century]]
 | [[2305]] ||colspan=2| [[2311]] || [[2322]] || [[2333]] || [[2339]] ||colspan=2| — || [[2350]] || [[2361]] || [[2367]] ||colspan=2| [[2378]] || [[2389]] ||colspan=2| [[2395]]
|-
|}

{| class="wikitable"
|+ 400-year cycle
|-
! 0–99
| 6 || 17 || 23 || 34 || 45 || 51 || 62 || 73 || 79 || 90 ||
|-
! 100–199
| 102 || 113 || 119 || 130 || 141 || 147 || 158 || 169 || 175 || 186 || 197
|-
! 200–299
| 209 || 215 || 226 || 237 || 243 || 254 || 265 || 271 || 282 || 293 || 299
|-
! 300–399
| 305 || 311 || 322 || 333 || 339 || 350 || 361 || 367 || 378 || 389 || 395
|}

=== Julian Calendar ===
In the now-obsolete Julian calendar, the fourteen types of year (seven common, seven leap) repeat in a [[solar cycle (calendar)|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 11, 22 and 28 of the cycle are common years beginning on Sunday. 2017 is year 10 of the cycle. Approximately 10.71% of all years are common years beginning on Sunday.

{| class="wikitable"
|+ Julian common years starting on Sunday
!scope=row| Decade
!colspan=2| 1st !!colspan=2| 2nd !!colspan=2| 3rd !!colspan=2| 4th !!colspan=2| 5th !!colspan=2| 6th !!colspan=2| 7th !!colspan=2| 8th !!colspan=2| 9th !!colspan=2| 10th
|-
! style="background-color:#efefef;" | 15th century
|colspan=2| [[1402]] || [[1413]] || [[1419]] ||colspan=2| [[1430]] ||colspan=2| — || [[1441]] || [[1447]] ||colspan=2| [[1458]] ||colspan=2| [[1469]] ||colspan=2| [[1475]] ||colspan=2| [[1486]] ||colspan=2| [[1497]]
|-
! style="background-color:#efefef;" | 16th century
|colspan=2| [[1503]] ||colspan=2| [[1514]] ||colspan=2| [[1525]] ||colspan=2| [[1531]] ||colspan=2| [[1542]] || [[1553]] || [[1559]] ||colspan=2| [[1570]] ||colspan=2| — || [[1581]] <!-- Wikipedia year articles refer to Gregorian years from 1582 --> || 1587 ||colspan=2| 1598
|-
! style="background-color:#efefef;" | 17th century
|colspan=2| 1609 ||colspan=2| 1615 ||colspan=2| 1626 ||colspan=2| 1637 ||colspan=2| 1643 ||colspan=2| 1654 ||colspan=2| 1665 ||colspan=2| 1671 ||colspan=2| 1682 || 1693 || 1699
|-
! style="background-color:#efefef;" | 18th century
|colspan=2| 1710 ||colspan=2| — || 1721 || 1727 ||colspan=2| 1738 ||colspan=2| 1749 ||colspan=2| 1755 ||colspan=2| 1766 ||colspan=2| 1777 ||colspan=2| 1783 ||colspan=2| 1794
|-
! style="background-color:#efefef;" | 19th century
|colspan=2| 1805 ||colspan=2| 1811 ||colspan=2| 1822 || 1833 || 1839 ||colspan=2| 1850 ||colspan=2| — || 1861 || 1867 ||colspan=2| 1878 ||colspan=2| 1889 ||colspan=2| 1895
|-
! style="background-color:#efefef;" | 20th century
|colspan=2| 1906 ||colspan=2| 1917 ||colspan=2| 1923 ||colspan=2| 1934 ||colspan=2| 1945 ||colspan=2| 1951 ||colspan=2| 1962 || 1973 || 1979 ||colspan=2| 1990 ||colspan=2| —
|-
! style="background-color:#efefef;" | 21st century
| 2001 || 2007 ||colspan=2| 2018 ||colspan=2| 2029 ||colspan=2| 2035 ||colspan=2| 2046 ||colspan=2| 2057 ||colspan=2| 2063 ||colspan=2| 2074 ||colspan=2| 2085 ||colspan=2| 2091
|}