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September 17

Day 261 of 366 · ISO week 38 · Virgo · Summer (Northern Hemisphere)

September 17 is the 261st day of the year in the Gregorian calendar; 105 days remain until the year's end. It falls in summer (northern hemisphere) and under the astrological sign of Virgo.

Day of year
261
Days remaining
105
ISO week
38
Zodiac
Virgo
Season
Summer
Sun declination
+1.0°

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 17 ≈ +1.0°
+23° −23° +1.0°
Computed via Cooper's formula. Positive declination = Sun north of the celestial equator (Northern Hemisphere summer).

On September 17 the Sun's declination is approximately +1.0°. At this latitude the Sun is north of the celestial equator, giving the Northern Hemisphere longer 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 17.

Position in the year

Position in the calendar year — day 261 of 366 (with 105 remaining)
JanFebMarAprMayJunJulAugSepOctNovDec Sep 17

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 (261)3^2 × 29 · composite (no)
Days remaining (105)3 × 5 × 7
Date code DDMMYYYY17092026 · no palindrome in next 200 years
Sun declination+1.01° (Cooper approximation)
Distance from solstice89 days

Cross-references

The 17th of every other month

Adjacent days

Days nearby

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