Dates That Don't Exist (2015)

3 days ago

The Gregorian calendar, established in 1582 under papal bull inter gravissimas, reduced the year length from 365.25 to 365.2425 days and introduced the modern leap year system.
To correct a 10-day drift between the Julian and Gregorian calendars, the dates October 5-14, 1582 were removed, effectively erasing those days from history.
Ruby's DateTime correctly rejects impossible Gregorian dates like October 5, 1582, while Python's datetime and Perl's DateTime module allow them without error.
The ncal command with a country code ('-s' flag) handles calendar adjustments differently per nation but still misses some historical shifts, like Sweden's in the 1700s.

Date parsing is unreliable: ISO date-only strings are parsed as UTC, while other formats are parsed as local time, causing timezone shifts.
Months are 0-indexed and Date objects are mutable, leading to silent rollover and unexpected changes.
Timezones and DST cause off-by-one errors: getDate() vs getUTCDate() can return different days, and DST days are not always 24 hours.

In 2017, a team implemented Tetris as a Game of Life simulation using a 30 trillion pixel grid and a programmable CPU.
Leap seconds, used to sync UTC with Earth's rotation, are set to be abolished by 2035, allowing drift between the two.
The backslash character scarcely existed before 1930 and was added to ASCII for mathematical notation, becoming a key due to its uselessness.

Teaching at the University of Oxford began around 1096, making it older than the Aztec Empire, which started in 1325.
Oxford is not the oldest university; the University of al-Qarawiyyin (founded 859) and the University of Bologna (1088) are older.
The Aztec Empire's dominance lasted less than a century, from 1428 to 1521, while the White House has stood since 1792.

Leap seconds are controversial due to Earth's variable rotation, affecting timekeeping.
Navigation satellites like GPS, Galileo, and BeiDou use monotonic clocks unaffected by leap seconds, broadcasting offset to UTC.
Leap seconds are pre-announced months in advance, transmitted with truncated week number and day to save bandwidth.

Local mean time (LMT) varied by region until railways necessitated standardization, leading to the adoption of GMT.
GMT is based on solar time, but its irregularities led to the development of atomic time and UTC, which includes leap seconds for corrections.
Computers use Unix time, measured from Jan 1, 1970, and handle time via system time, RTC, and NTP, with challenges like the Year 2038 problem and leap seconds.

Date parsing is unreliable: ISO date-only strings are parsed as UTC, while other formats are parsed as local time, causing timezone shifts.
Months are 0-indexed and Date objects are mutable, leading to silent rollover and unexpected changes.
Timezones and DST cause off-by-one errors: getDate() vs getUTCDate() can return different days, and DST days are not always 24 hours.

In 2017, a team implemented Tetris as a Game of Life simulation using a 30 trillion pixel grid and a programmable CPU.
Leap seconds, used to sync UTC with Earth's rotation, are set to be abolished by 2035, allowing drift between the two.
The backslash character scarcely existed before 1930 and was added to ASCII for mathematical notation, becoming a key due to its uselessness.

Teaching at the University of Oxford began around 1096, making it older than the Aztec Empire, which started in 1325.
Oxford is not the oldest university; the University of al-Qarawiyyin (founded 859) and the University of Bologna (1088) are older.
The Aztec Empire's dominance lasted less than a century, from 1428 to 1521, while the White House has stood since 1792.

Leap seconds are controversial due to Earth's variable rotation, affecting timekeeping.
Navigation satellites like GPS, Galileo, and BeiDou use monotonic clocks unaffected by leap seconds, broadcasting offset to UTC.
Leap seconds are pre-announced months in advance, transmitted with truncated week number and day to save bandwidth.

Local mean time (LMT) varied by region until railways necessitated standardization, leading to the adoption of GMT.
GMT is based on solar time, but its irregularities led to the development of atomic time and UTC, which includes leap seconds for corrections.
Computers use Unix time, measured from Jan 1, 1970, and handle time via system time, RTC, and NTP, with challenges like the Year 2038 problem and leap seconds.

Hasty Briefsbeta