Historical milestones commemorated on September 14

Historical events commemorated on September 14 include the implementation of the Gregorian calendar reform by Pope Gregory XIII in 1582. This reform introduced a new leap year rule to correct the Julian calendar, creating a discrepancy that currently stands at 13 days.

Other notable historical milestones include Napoleon I's military campaigns, such as his 1812 invasion of Russia, and the 1923 rise of Spanish dictator Miguel Primo de Rivera, who seized power in Barcelona by overthrowing the parliamentary government.