MS Docs

System.Globalization.Calendar

The Calendar abstract base class represents a calendar. A calendar is a system for measuring time based on the position of Earth in its orbit around the Sun or the Moon's position in relation to Earth. The Calendar class provides methods for date arithmetic, determining leap years, and other calendar-specific calculations. It is the foundation for culture-specific date and time operations.

Overview

Members

Methods

Properties

Examples

Inheritance

Object → Calendar

Namespace

System.Globalization

Assembly

System.Runtime.dll

Members

Name	Type	Description
AddMonths	Method	Adds months to a DateTime value.
AddYears	Method	Adds years to a DateTime value.
TwoDigitYearMax	Property	Gets or sets the last year of a 100-year range that can be represented by a two-digit year.

Methods

AddMonths(DateTime time, int months) - Returns a new DateTime that adds the specified number of months.
AddYears(DateTime time, int years) - Returns a new DateTime that adds the specified number of years.
IsLeapYear(int year) - Determines whether the specified year is a leap year.
GetDaysInMonth(int year, int month) - Returns the number of days in the specified month and year.
GetEra(DateTime time) - Returns the era for the specified date and time.

Properties

TwoDigitYearMax – Gets or sets the last year of a 100-year range that can be represented by a two-digit year.
AlgorithmType – Gets the type of calendar algorithm used.
MaxSupportedDateTime – Gets the latest date and time that the calendar can represent.
MinSupportedDateTime – Gets the earliest date and time that the calendar can represent.

Example

Calculate the date 6 months from today using the GregorianCalendar implementation of Calendar:

using System;
using System.Globalization;

class Program
{
    static void Main()
    {
        Calendar cal = new GregorianCalendar();
        DateTime today = DateTime.Today;
        DateTime future = cal.AddMonths(today, 6);
        Console.WriteLine($"Today: {today:d}");
        Console.WriteLine($"Six months later: {future:d}");
    }
}