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CalendarType

is an option that determines the calendar system in which all dates are to be interpreted and output.

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Scope  
Applications  
Properties & Relations  
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CalendarType

CalendarType

is an option that determines the calendar system in which all dates are to be interpreted and output.

Details

  • CalendarType is typically used to specify how to interpret dates without a calendar, or to convert date objects from another calendar.
  • In general, the default value of CalendarType is "Gregorian".
  • Date calendars can be given as named objects, like "Gregorian" or "Julian", or in the form {"name",<|param1val1,param2value2,…|>} for calendars with nondefault parameter values.
  • Calendar parameters include:
  • "YearZero"whether the calendar includes a year zero
    "StartOfDay"beginning instant of the day
    "Location"reference geodetic position for astronomical calendars
  • Default calendar parameters can be obtained using CalendarData["name"].
  • Prominent arithmetic calendars include:
  • "Gregorian"proleptic Gregorian calendar
    "Islamic"tabular Islamic calendar
    "Jewish"arithmetic lunisolar Hebrew calendar
    "Julian"proleptic Julian calendar
  • Additional arithmetic calendars are given by CalendarData["ArithmeticCalendar"]. Astronomical calendars are given by CalendarData["AstronomicalCalendar"].

Examples

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Basic Examples  (3)

Get the current date on the Jewish calendar:

Wolfram Language code: DateObject[CalendarType -> "Jewish"]

Represent a Julian calendar date:

Wolfram Language code: DateObject[{2026, 8, 4}, CalendarType -> "Julian"]

Get the next month on the Chinese lunar calendar:

Wolfram Language code: NextDate["Month", CalendarType -> "Chinese"]

Parameterized calendars can be used to adjust the values for "StartOfDay" or "YearZero" handling:

Wolfram Language code: DateObject[{1, 1, 1}, CalendarType -> "Gregorian"] - Quantity[2, "Days"]
Wolfram Language code: DateObject[{1, 1, 1}, CalendarType -> {"Gregorian", <|"YearZero" -> True|>}] - Quantity[2, "Days"]

Scope  (3)

Represent the month of Ramadan on the Islamic calendar:

Wolfram Language code: DateInterval[DateObject[{1446, 9}, "Month", "Islamic"], CalendarType -> "Islamic"]

Compute a date range returning dates in the Islamic calendar:

Wolfram Language code: DateRange[DateObject[{2022, 1, 1}], DateObject[{2022, 3, 1}], "Week", CalendarType -> "Islamic"]

Construct a TimeSeries object with dates in the "Julian" calendar:

Wolfram Language code: TimeSeries[Range[5], {DateObject[{2024, 2, 14}, CalendarType -> "Julian"], Automatic, "Day"}]

Convert those dates to the "Islamic" calendar:

Wolfram Language code: TimeSeries[%, CalendarType -> "Islamic"]
Wolfram Language code: Normal[%]

Applications  (1)

Express the current instant in all available calendars:

Wolfram Language code: AssociationMap[DateObject[Now, CalendarType -> #]&, CalendarData[]]//Dataset

Properties & Relations  (2)

The list of available calendar types can be found using CalendarData:

Wolfram Language code: CalendarData["DateCalendar"]

This includes both arithmetic and astronomical calendar types:

Wolfram Language code: CalendarData["ArithmeticCalendar"]
Wolfram Language code: CalendarData["AstronomicalCalendar"]

The default calendar type in DateObject is "Gregorian":

Wolfram Language code: range = DateRange[DateObject[{2022, 1, 1}], DateObject[{2022, 2, 1}], "Week"]

Change the output for the same dates to the "Jewish" calendar:

Wolfram Language code: DateRange[DateObject[{2022, 1, 1}], DateObject[{2022, 2, 1}], "Week", CalendarType -> "Jewish"]
Wolfram Language code: % == range

Change the calendar of the input dates as well:

Wolfram Language code: DateRange[DateObject[{2022, 1, 1}, CalendarType -> "Jewish"], DateObject[{2022, 2, 1}, CalendarType -> "Jewish"], "Week", CalendarType -> "Jewish"]

The date range now represents a different period in time:

Wolfram Language code: % == range
Wolfram Research (2012), CalendarType, Wolfram Language function, https://reference.wolfram.com/language/ref/CalendarType.html (updated 2020).

Text

Wolfram Research (2012), CalendarType, Wolfram Language function, https://reference.wolfram.com/language/ref/CalendarType.html (updated 2020).

CMS

Wolfram Language. 2012. "CalendarType." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2020. https://reference.wolfram.com/language/ref/CalendarType.html.

APA

Wolfram Language. (2012). CalendarType. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/CalendarType.html

BibTeX

@misc{reference.wolfram_2026_calendartype, author="Wolfram Research", title="{CalendarType}", year="2020", howpublished="\url{https://reference.wolfram.com/language/ref/CalendarType.html}", note=[Accessed: 12-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_calendartype, organization={Wolfram Research}, title={CalendarType}, year={2020}, url={https://reference.wolfram.com/language/ref/CalendarType.html}, note=[Accessed: 12-June-2026]}