Date Calculator - Holidays, Observances, Celebrations, Historical, National, International, and Other Key Dates

This simple calculator tool allows you to calculate/generate dates for important holidays, national and international days, and other kay days. The output can be the date for a single year (1582 to 2500). The output can also be the dates for a range of years from 1582 to 2500. The calculator uses the Gregorian calendar. This calculator is especially useful if you wish to know the weekday for a given holiday in a given year (for example, is New Year's Day on a Monday in 2029?). Several common date output formats are available. If the important date you are looking for is not included below, please use our Custom Date Calculator/Generator.