Have you ever wondered why we use the calendar we have now rather than the old Roman Julian calendar ? The answer lies in a rather peculiar event that took place in September 1752—the “lost days” that still puzzle and intrigue historians today.
The Gregorian Calendar Reform
By the mid-18th century, the Julian calendar, introduced by Julius Caesar in 46 BC, had fallen significantly out of sync with the actual solar year. This was because the Julian calendar assumed that the solar year was exactly 365.25 days long, when in fact it is slightly shorter, at around 365.2422 days.
Over the centuries, this small discrepancy had added up, causing the equinoxes and solstices to drift away from their traditional calendar dates. In 1582, Pope Gregory XIII introduced a new calendar to address this issue – the Gregorian calendar that we use today.
The key change was to remove 10 days from the calendar, aligning the equinoxes and solstices with their proper dates once more. This was achieved by declaring that the day after 4th October 1582 would be 15th October 1582.
The 11 Lost Days of September 1752
While the Gregorian calendar reform was adopted relatively quickly across Catholic Europe, Protestant countries were more resistant to the changes. It wasn’t until 1752 that the British Empire, including the American colonies, finally made the switch.
When they did, it caused quite a stir. On 2nd September 1752, the date was followed not by the 3rd but by the 14th – effectively removing 11 days from the calendar. This meant that anyone with a birthday during that time (such as the philosopher John Locke) suddenly found their special day had been erased from the records.
Understandably, the public was quite alarmed by this drastic change. Riots even broke out in some areas, with people demanding, “Give us back our 11 days!” Clergy had to remind their congregations that the stars and moon were still in their proper places and that the change was necessary to keep the calendar aligned with the equinoxes.
The Practical Impacts
The lost days had significant practical impacts, too. For one, they caused all kinds of administrative headaches, as records, contracts, and transactions had to be hastily adjusted. There were also issues around tax and interest calculations and concerns about how to handle things like criminal sentences and rent payments.
At the same time, the start of the year, which had been in March, was moved to the 1st of January. However, the tax office didn’t like that so they continued to use the old start of the year. which is why the tax year ends in April in the UK (they did account for the 11 days though).
Interestingly, the change also affected people’s birthdays and the dates of important events. For example, George Washington’s birthday, which had been celebrated on 11 February, was now marked on 22 February instead.
So, while the Gregorian calendar reform was an important step in keeping our calendar aligned with the solar year, the transition was certainly chaotic and controversial. The 11 lost days of September 1752 serve as a fascinating historical footnote, a reminder of how even small changes to our timekeeping can have far-reaching consequences.
