Calendar Adjustment Day - September 2
Mon, Sep 2, 2024

Calendar Adjustment Day

Calendar Adjustment Day, observed annually on September 2, marks a significant shift in timekeeping history when the New Year’s celebration was officially moved to January 1st. This day commemorates the adoption of the Gregorian calendar, which required an adjustment period by omitting certain days to realign the calendar year with the astronomical year.


The transition to the Gregorian calendar was enacted by the British Calendar Act of 1751, leading Britain to switch from the Julian calendar. This adjustment meant that after going to sleep on September 2, 1752, people woke up on September 14, effectively “losing” 11 days. This change aimed to correct discrepancies with the astronomical year and resulted in the standardization of celebrating New Year’s Day on January 1. The modification led to public unrest, as many traditional holidays, particularly Easter, were shifted to new dates. Historical documents from this period began to differentiate dates as either “Old Style” or “New Style.”

Interesting Facts

  • The Gregorian calendar was initially designed to more accurately predict Easter.
  • The calendar reform was not crafted by Pope Gregory XIII himself but by his commission, including physician Aloysius Lilius and astronomer Christopher Clavius.
  • The first printed Gregorian calendars appeared in 1582.
  • Many Protestants initially criticized the new calendar as a Catholic innovation.
  • Astronomers sometimes use the Julian calendar for historical date calculations to avoid confusion with events that occurred before the Gregorian reform.

How to take part

Consider switching back to a printed desk calendar to appreciate the tactile aspect of marking time. Celebrate by marking significant dates and planning ahead. Engage with historical dramas or documentaries that explore the impact of losing 11 days, such as films or series related to time shifts.

When is Calendar Adjustment Day celebrated in 2024?

Calendar Adjustment Day is observed on September 2 each year.


Weekday Month Day Year
Monday September 2 2024
Tuesday September 2 2025
Wednesday September 2 2026
Thursday September 2 2027
Saturday September 2 2028
Sunday September 2 2029

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