Date Calculator
Add or subtract days, weeks or months to a date.
Addieren oder subtrahieren Sie Tage, Wochen, Monate oder Jahre zu einem Datum.
Note: These calculations are for informational purposes only and do not replace professional tax or financial advice. All information without guarantee.
Frequently Asked Questions
How do I add days to a date?
Add the number of days to the current date, accounting for month lengths and year boundaries. For example, January 28 plus 5 days equals February 2 (in a non-leap year).
How do I calculate the weekday for any date?
Use Zeller's formula or the doomsday algorithm to calculate the weekday mathematically. Or simply count days from a known reference date and divide by 7 to find the remainder.
What is the Date Calculator?
The date calculator adds or subtracts days, weeks, months or years to/from a date and shows the result with the day of the week.
How does the Date Calculator work?
Enter a starting date and the time span to add or subtract. The calculator determines the target date and shows the day of the week, calendar week and day of the year.
Key Data and Facts
Leap year rule: divisible by 4 = leap year, divisible by 100 = not, divisible by 400 = yes. 29 February only in leap years.
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