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Calendar Package Symbol

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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}.

MORE INFORMATION

To use DateQ, you first need to load the Calendar Package using Needs["Calendar`"].

The following options can be given:

Calendar

Automatic

specifies which calendar system to use

The default calendar is the usual Western (American) calendar, but can be changed with the Calendar option.

Valid settings for Calendar are Automatic, Julian, Gregorian, Islamic, and Jewish.

EXAMPLES

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Basic Examples (5)

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:

Needs["Calendar`"]

The default British/American calendar deletes the dates September 3 to 13, 1752:

Options (6)