March 13 (calendar date)

Calendar position and seasonal context

The date sits near the midpoint of March and often occurs during late winter or early spring in the Northern Hemisphere and late summer or early autumn in the Southern Hemisphere. Astronomical events such as the vernal equinox usually fall later in March (around March 20–21), so March 13 is commonly a prelude to that seasonal transition. Astrologically, this date lies under the sign of Pisces.

Notable events (examples)

• 1781: William Herschel observed the planet Uranus for the first time, a discovery that expanded the known Solar System.
• 1881: Tsar Alexander II of Russia was assassinated on this date, an event with major political repercussions for the Russian Empire.
• 2013: Cardinal Jorge Mario Bergoglio was elected Pope Francis, a moment of global interest for the Roman Catholic Church.

Uses, observances and commemorations

Specific holidays and observances on March 13 vary by country and culture. In many liturgical calendars the date can fall during Lent, and religious observances tied to that season will influence local commemorations. Secular anniversaries, local civic days and personal celebrations (birthdays, anniversaries) are also commonly observed on fixed calendar dates such as March 13.

Distinctions and interesting facts

Because its ordinal number changes in leap years, March 13 illustrates a basic effect of calendar correction. It sits one day before March 14 (Pi Day in popular culture) and may coincide with the start or approach of daylight saving adjustments in jurisdictions that use them. Historical records for a given March 13 may differ depending on whether dates are recorded under the Julian or Gregorian systems, so historians take care when comparing older events across different calendars.

For further chronological and calendrical context, consult resources on leap-year rules and the structure of the Gregorian calendar.