January 20
January 20 is the 20th day of the year in the Gregorian calendar; 346 days remain until the year's end. It falls in winter (northern hemisphere) and under the astrological sign of Aquarius.
Day of year
20
Days remaining
346
ISO week
3
Zodiac
Aquarius
Season
Winter
Sun declination
-20.3°
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
Computed via Cooper's formula. Positive declination = Sun north of the celestial equator (Northern Hemisphere summer).
On January 20 the Sun's declination is approximately -20.3°. 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 January 20.
Position in the year
Holidays & observances
- Inauguration Day (United States, every fourth year — 21st-Amendment date)
Events
A selection of widely-documented historical events that took place on this date. Years marked BCE follow standard astronomical convention.
- 1265 — The first English parliament called by Simon de Montfort assembled at Westminster. ↗(761 years ago)
- 1841 — Hong Kong was occupied by the British during the First Opium War. ↗(185 years ago)
- 1937 — Franklin D. Roosevelt was inaugurated for a second term — the first U.S. presidential inauguration on January 20. ↗(89 years ago)
- 1981 — Iran released the 52 American hostages, after 444 days of captivity, minutes after Ronald Reagan's inauguration. ↗(45 years ago)
- 2009 — Barack Obama became the first African-American President of the United States. ↗(17 years ago)
Notable births
Notable deaths
Numerical & calendrical curiosities
| Day-of-year (20) | 2^2 × 5 · composite (no) |
|---|---|
| Days remaining (346) | 2 × 173 |
| Date code DDMMYYYY | 20012026 · no palindrome in next 200 years |
| Sun declination | -20.33° (Cooper approximation) |
| Distance from solstice | 31 days |