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April 18

Day 109 of 366 · ISO week 16 · Aries · Spring (Northern Hemisphere)

April 18 is the 109th day of the year in the Gregorian calendar; 257 days remain until the year's end. It falls in spring (northern hemisphere) and under the astrological sign of Aries.

Day of year
109
Days remaining
257
ISO week
16
Zodiac
Aries
Season
Spring
Sun declination
+10.9°

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. April 18 ≈ +10.9°
+23° −23° +10.9°
Computed via Cooper's formula. Positive declination = Sun north of the celestial equator (Northern Hemisphere summer).

On April 18 the Sun's declination is approximately +10.9°. 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 April 18.

Position in the year

Position in the calendar year — day 109 of 366 (with 257 remaining)
JanFebMarAprMayJunJulAugSepOctNovDec Apr 18

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.

Notable births

Notable deaths

Numerical & calendrical curiosities

Day-of-year (109)109 · prime
Days remaining (257)257
Date code DDMMYYYY18042026 · no palindrome in next 200 years
Sun declination+10.87° (Cooper approximation)
Distance from solstice63 days

Cross-references

The 18th of every other month

Adjacent days

Days nearby

Themes: paul-revere-ridesf-earthquakeeinstein-death

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