74 votes
Accepted

Why does the amount of days in an year on average of the Gregorian calendar only have 4 decimal places (365.2425)?

Why? Because there was no point. First, according to more modern astronomical measurements, the current length of the year is closer to about 365.2422 days, so they would've been relatively less ...
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24 votes

What is the reason that not all roman emperors named a month after them?

Suetonius has this to report about Tiberius, the second emperor and the third Caesar: [H]e at first played a most unassuming part, almost humbler than that of a private citizen. Of many high ...
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23 votes
Accepted

Why does Japan celebrate the Gregorian New Year but China still celebrates Chinese New Year?

The short answer is because the Japanese government does not designate the old lunisolar new year as a public holiday. Officially, China does in fact celebrate New Year's Day (元旦) on the Western (...
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20 votes
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How come every culture on the planet has a different calendar, yet follow the same system for a week?

We have an enormous amount of evidence for the ancient Babylonian calendar, but no evidence at all for a seven-day week in ancient Babylonia. In the ancient world there were two forms of the seven-...
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  • 9,473
20 votes
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Was Mid-Night always considered the transition point between two days in Gregorian/Julian Calendars?

It wasn't simple to track time at night until the invention of mechanical clocks. Before that the breakpoint between days was sunrise (early Roman), solar midnight (later Roman), or sunset (Athenians, ...
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19 votes
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Why is the leap day on February 29th?

The ancient Romans used to have the new year at the end of February. To fit the lunar and solar calendars, an extra month was sometimes added after February. This practice continued even after the ...
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  • 5,401
19 votes

Why does the amount of days in an year on average of the Gregorian calendar only have 4 decimal places (365.2425)?

The Gregorian Calendar was introduced (to the Catholic World) in 1582, the result of preparation over the preceding five or so years. However the popularization of decimal fractions would wait another ...
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17 votes
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How was the current month and day disseminated to the townspeople of Medieval Europe?

For the most part, church and celestial events. In particular, midsummer and midwinter and the equinoxes were both easy to detect and were important events, at least in the colder climates of Europe. ...
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16 votes
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How is the year "753 BC" given in ancient legends about the founding of Rome?

I am not sure about legends (are there any specifying Rome's foundation year? I suspect it might be in the form of "X years since the sack of Troy"). But since your question also asked about "ancient ...
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15 votes

When did Europeans make Sunday rather than Saturday the seventh day?

In the 1970s the day numbering was standardized worldwide, culminating in an UN decision. The current version of the standard is ISO 8601. Some countries were more timely than others in adopting this ...
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15 votes
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Why was the date moved by 10 days instead of 9 during Gregorian calendar reform?

The date was moved by ten days because that's how many days the Julian calendar was off by. You may have thought the time skip was meant to compensate for the drift of nine days between 325 and 1582. ...
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  • 95.9k
14 votes

What is the reason that not all roman emperors named a month after them?

Actually several did: Caligula renamed September to Germanicus (Suetonius, Caligula, 15) in memory of his father. Nero renamed April to Neronium (Suetonius, Nero, 55).
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  • 4,258
13 votes
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Why have both July and August 31 days?

First, the answer to your second question. [W]ho invented that calender? The current calendar that most of the western world uses is Gregorian Calendar1, which is an improvement over Julian ...
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  • 3,013
12 votes

Has there ever been a month with 32 days?

Not that I know of, but in 1712 in Sweden, February had 30 days. Sweden, being a Protestant country, was initially suspicious of the "papist" Gregorian calendar, but decided to adopt it in the early ...
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  • 5,401
11 votes
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How did historians sync up historical dates of different cultures?

The term you're looking for is chronology (Wikipedia's article on the subject is rather sub-par). In general, there are two major ways of synchronizing dates. Find an event recorded in more than one ...
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  • 8,322
10 votes

Which calendar to use in English for non-European countries?

A modern secondary historical paper or book should always use the Gregorian Calendar and the era of Exiguus. For pre-Gregory dates the proleptic calendar should be used. The reason for this is so that ...
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10 votes
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When was the change from kalends, ides and nones to numbers

This is covered by Bonnie Blackburn and LeoFranc Holford-Strevens in their book The Oxford Companion to the Year: An exploration of calendar customs and time-reckoning (1999, reprinted with ...
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10 votes

Which months were added during the Roman Empire?

The original Roman calendar is believed to have been a lunar calendar, which may have been based on one of the Greek lunar calendars. As the time between new moons averages 29.5 days, its months were ...
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  • 1,258
10 votes
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Has there ever been a month with 32 days?

It seems the Julian calendar had a month with 32 days on leap years at one point: An inscription has been discovered which orders a new calendar to be used in Asia to replace the previous Greek ...
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10 votes
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Has anyone created a binary calendar?

The core issue is that the purpose of a calendar is to track astronomical events, and in particular, their relations. The three that are universally tracked are the three that are obvious to anyone: ...
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10 votes
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What was the calendar used by ancient Palmyrenes?

The year 311 BC is the anchor for the beginning of the Seleucid era: The Seleucid era ("SE") or Anno Graecorum (literally "year of the Greeks" or "Greek year"), ...
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9 votes

What, if any, celebrations or commemorations were done in 1000 AD?

Most people in Christian medieval Europe who gave the matter any thought seem to have expected that the end of the first millennium would also be accompanied by the end of the world. However, it is ...
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  • 76.2k
9 votes

In Ancient Cultures - How was a New Moon identified when it can never be seen?

In Jewish custom, all calendar questions were decided by the court (Synedrion). It was a duty of everyone who spotted the new Moon to report to this court as soon as possible. But of course, the new ...
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9 votes

What calendars were used in Eastern Rome?

Many different local calendars were used in the eastern and western parts of the Roman empire. The Julian calendar introduced about 44 BC was the official calendar of the Roman republic and empire ...
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  • 16.9k
9 votes

When did the current 7-day week cycle begin?

Timothy is somewhat correct with identifying Babylon, however the Babylonians only borrowed the system. Most of our time keeping dates all the way back to ancient Sumeria (2600BC-ish?) and is ...
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  • 2,674
9 votes

Was the date skip of the Gregorian calender reform understood to skip weekdays accordingly?

The change over to the Gregorian Calendar happened over a period of over 300 years across the western world. Consequently the number of skipped days varied by country depending on when they changed ...
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  • 18.1k
9 votes

Has there ever been a month with 32 days?

Of course it depends whose months you look at. Part of the decimalization project in revolutionary France was Claude Boniface Collignon's proposals for decimalizing time. He called for ten "solar ...
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  • 27.3k
8 votes

Why does the Gregorian calendar start where it does?

The Roman calendar (on which the Gregorian calendar was based) was synchronized with a celestial event: the lunar cycle. Originally, each Roman month began on the first day of the new moon. However, ...
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  • 37.2k
8 votes

In Russia, are the anniversaries of the various events that occurred in 1917 and '18 observed according to the Old Style or the New Style calendar?

None of the events are celebrated in Russia nowadays. In Soviet times, only the day of the October Revolution was celebrated, on the 7th November, which is according to the New-Style calendar. In ...
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  • 219
8 votes
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When did Europeans make Sunday rather than Saturday the seventh day?

Sunday is the first day of the week and Saturday is the seventh. That conforms to a tradition that goes back at least to ancient Jews long before Christianity. It should be noted that other ways of ...
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