Which days were deleted in 1582?

In the countries that adopted the reform immediately, 4 October 1582 was followed directly by 15 October 1582.

Why was the calendar changed?

The Julian year was about eleven minutes too long, so the equinox had drifted ten days and the date of Easter was calculated from a false starting point.

Does Buy The Time use this calendar?

Yes. All minutes are recorded in UTC on the proleptic Gregorian calendar, including dates before 1582.

October 15, 1582

1582-10-15 00:00 UTC

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The Gregorian calendar begins

Catholic Europe wakes on 15 October, ten days having been deleted overnight to correct the drifting Julian year.

Source ↗

What happened in this minute

The Julian year was eleven minutes too long, and by the sixteenth century the spring equinox had drifted ten days from its assumed date, unmooring the calculation of Easter.

Pope Gregory XIII's reform deleted 5 to 14 October 1582 and changed the leap-year rule so that century years divide by four hundred. Spain, Portugal, Poland and much of Italy adopted it immediately; Britain waited until 1752 and Russia until 1918.

This is the minute the modern civil calendar starts, which makes it the reference frame for almost every other timestamp in this registry.

Questions and answers

Which days were deleted in 1582?: In the countries that adopted the reform immediately, 4 October 1582 was followed directly by 15 October 1582.
Why was the calendar changed?: The Julian year was about eleven minutes too long, so the equinox had drifted ten days and the date of Easter was calculated from a false starting point.
Does Buy The Time use this calendar?: Yes. All minutes are recorded in UTC on the proleptic Gregorian calendar, including dates before 1582.