Recognised as Date
23 September 1216
- Friday
- Q3
- Leap year
- Week 38
- Libra
23 September 1216 falls on a Friday in the proleptic Gregorian calendar, which did not yet exist at the time. It is day 267 of 366 in 1216, a leap year, falling in week 38 and quarter 3. Its Unix timestamp is -23,770,972,800.
Calendar position
Day of the weekFridayproleptic Gregorian; contemporaries used the Julian calendar and would have named a different day
Day of the month23rd
Day of the year267 of 366
Days remaining in the year99
Days elapsed in the year266
ISO week numberWeek 38ISO 8601, weeks start on Monday
Week of the month4th
Occurrence in the month4th Friday
QuarterQ3 1216
Year1216
Days in the month30
Leap yearYes, 366 days
This date in other formats
ISO 86011216-09-23
British (D/M/Y)23/09/1216
American (M/D/Y)09/23/1216
Long formFriday 23rd September 1216
RFC 2822Fri, 23 Sep 1216 00:00:00 GMT
Compact12160923
In wordsthe 23rd of September, one thousand, two hundred and sixteen
Julian calendar equivalent16 September 1216the date contemporaries would have written, before the Gregorian calendar existed
This date in other calendars
Hebrew2 Tishri 4977the Hebrew calendar has been fully algorithmic since the ninth century, so this is exact
Islamic (tabular)2 Jumada II 613 AHthe tabular reckoning; the calendar in religious use begins each month on an actual crescent sighting, so expect a day either way
Persian (arithmetic)1 Mehr 595the arithmetic (Birashk) calendar; the official Solar Hijri calendar takes its new year from the astronomical equinox at Tehran
Rata Die444,036days since 1 January 1 CE in the proleptic Gregorian calendar, the pivot every conversion here runs through
Unix time & day counts
Unix timestamp-23,770,972,800seconds since 1 January 1970, midnight UTC
Unix timestamp (ms)-23,770,972,800,000
Relationship to the epoch275,127 days before the Unix epoch
Julian Day Number2,165,461midnight UTC
Days since 1 January 1900-249,560
Days since 1 January 2000-286,084
Moon phase
PhaseWaxing crescentthe same phase everywhere on Earth at the same instant
Illuminated at 12:00 UTC12%≈to about 1%, by Meeus
Waxing or waningWaxing
Moon age at 12:00 UTC3 dayssince the previous new moon
Previous new moon20 September 1216
Next new moon19 October 1216
Previous full moon4 September 1216
Next full moon4 October 1216
Lit side, Northern HemisphereRight
Lit side, Southern HemisphereLeftthe same Moon seen from the other side of the equator; near the equator the lit side points up or down rather than to one side
PrecisionDates onlybefore 1700 or after 2150 the Earth's rotation is not known well enough to give a time, and a phase near midnight can land a day either side
Relative to today
These values depend on today’s date and change daily.
Today19 September 2026
Days ago295,842 days
In other terms809 years, 354 days and 18 hours
Weeks42263.1 weeks ago
Anniversary this yearin 4 days
Years elapsed809 complete years
Seasons & signs
Zodiac signLibraAir sign
Chinese zodiac yearRatthe animal changes at Chinese New Year, not 1 January
Season (Northern Hemisphere)Autumnmeteorological seasons, by whole months
Season (Southern Hemisphere)Spring
Easter Sunday that year17 April 1216
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