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DateQ

DateQ[{year, month, day}]
yields True if date {year, month, day} is a valid date in the current calendar system, and yields False otherwise.
DateQ[{year, month, day, hour, minute, second}]
date given in long form {year, month, day, hour, minute, second}.
  • The following options can be given:
CalendarAutomaticspecifies which calendar system to use
  • The default calendar is the usual Western (American) calendar, but can be changed with the Calendar option.
Needs["Calendar`"]
DateQ recognizes ordinary Western dates:
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Needs["Calendar`"]
DateQ will identify leap years. The year 2000 was a leap year:
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Needs["Calendar`"]
The year 1900 was not a leap year:
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Needs["Calendar`"]
By default, Mathematica uses the standard Western (British/American) calendar. The British/American calendar applies the Julian calendar to dates before 1752 and the Gregorian calendar after:
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Needs["Calendar`"]
The default British/American calendar deletes the dates September 3 to 13, 1752:
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