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September 21

Day 265 of 366 · ISO week 38 · Virgo · Summer (Northern Hemisphere)

September 21 is the 265th day of the year in the Gregorian calendar; 101 days remain until the year's end. It falls in summer (northern hemisphere) and under the astrological sign of Virgo.

Day of year
265
Days remaining
101
ISO week
38
Zodiac
Virgo
Season
Summer
Sun declination
-0.6°

External references

Curated jump-off points to the major almanacs, encyclopaedias and primary sources for this date.

Wikipedia: this day →Britannica: this day →LoC: Today in History →History.com: this day →On-This-Day.com →BBC: On This Day →NYT: this day →Time and Date →NASA APOD archive →U.S. Naval Observatory →Wolfram|Alpha →Wikidata →Google Books →JSTOR →Internet Archive →
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Astronomy

Solar declination through the year — the Sun's apparent latitude on Earth. September 21 ≈ -0.6°
+23° −23° -0.6°
Computed via Cooper's formula. Positive declination = Sun north of the celestial equator (Northern Hemisphere summer).

On September 21 the Sun's declination is approximately -0.6°. At this latitude the Sun is south of the celestial equator, giving the Northern Hemisphere shorter days than nights.

For specific rise/set times at your location, see the U.S. Naval Observatory, or the NASA APOD archive for any imagery published on a September 21.

Position in the year

Position in the calendar year — day 265 of 366 (with 101 remaining)
JanFebMarAprMayJunJulAugSepOctNovDec Sep 21

Holidays & observances

No widely-observed holidays catalogued for this day in our base set. See the external almanacs above for region-specific observances.

Events

A selection of widely-documented historical events that took place on this date. Years marked BCE follow standard astronomical convention.

No events currently catalogued for this day. External references may have more.

Notable births

No births currently catalogued for this day. External references may have more.

Notable deaths

No deaths currently catalogued for this day. External references may have more.

Numerical & calendrical curiosities

Day-of-year (265)5 × 53 · composite (no)
Days remaining (101)101
Date code DDMMYYYY21092026 · no palindrome in next 200 years
Sun declination-0.61° (Cooper approximation)
Distance from solstice90 days

Cross-references

The 21st of every other month

Adjacent days

Days nearby

All days