𝟐𝟏𝐬𝐭 𝐨𝐟 𝐅𝐞𝐛𝐫𝐮𝐚𝐫𝐲, 𝐦𝐚𝐫𝐤𝐬 𝐭𝐡𝐞 𝐢𝐧𝐭𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧 𝐨𝐟 𝐭𝐡𝐞 𝐆𝐫𝐞𝐠𝐨𝐫𝐢𝐚𝐧 𝐜𝐚𝐥𝐞𝐧𝐝𝐚𝐫.

Named after Pope Gregory XIII, who introduced it in 1582, the Gregorian calendar replaced the Julian calendar, which had been the most used calendar in Europe until this point.

In 45 BC, Julius Caesar ordered a calendar consisting of twelve months based on a solar year.

𝐒𝐨, 𝐰𝐡𝐲 𝐭𝐡𝐞 𝐜𝐡𝐚𝐧𝐠𝐞?

In 1582, it was discovered that the Julian Calendar was out by 10 days in regard to the tropical year and because the date of Easter was tied to the Spring Equinox, the Roman Catholic Church considered the seasonal drift in the date of Easter undesirable.

So in October of 1582, 10 days were removed from that month and the day after the 4th became the 15th. This was designed to bring the vernal equinox in line with the tropical year. 

The introduction of the calendar wasn't welcomed by everyone, for instance in England mobs protested, fearing they would lose wages for the missing days, plus they would lose 10 days of their life.

Their cry was “Give us back our 11 days!”—referring to the 10 days dropped plus the day of the calendar change itself.

The Julian calendar is still used as a religious calendar in parts of the Eastern Orthodox Church, as well as by the Amazigh people in Morocco, Libya, Algeria, and Tunisia (also known as the Berbers).

Today there is a disparity of 13 days from the original Julian calendar which will increase to 14 days by 2100. 

As they say….what a difference a day makes .