Anniversary calculator, adding and subtracting days, months and years to date
Calculator computes the new date after adding (or subtracting) given number of days, months or years to given date. It has the option to exclude Saturdays, Sundays and country-specific holidays from the date calculation.

Input data - start date and number of days to count#

Start date
Number of days/months/years to add/subtract
Don't includeSaturdaysSundaysPublic holidays
Your region
(needed to adjust holidays list)

Results - dates of computed anniversaries#

Start date2021-01-28 (Thursday)
50 days later2021-03-19 (Friday)
50 days before2020-12-09 (Friday)
50 months later2025-03-28 (Friday)
50 months before2016-11-28 (Monday)
50 years later2071-01-28 (Wednesday)
50 years before1971-01-28 (Thursday)
Days excluded while adding days (coming in the future)
Number of excluded saturdays
Number of excluded sundays
Number of excluded public holidays
Excluded public holidays
Total number of excluded days
Days excluded while subtracting days (from the past)
Number of excluded saturdays
Number of excluded sundays
Number of excluded public holidays
Excluded public holidays
Total number of excluded days
Anniversaries (days)
100 days anniversary2021-05-08 (Saturday)
1000 days anniversary2023-10-25 (Wednesday)
100 days before2020-10-20 (Tuesday)
1000 days before2018-05-04 (Sunday)
Anniversaries (months)
100 months anniversary2029-05-28 (Monday)
1000 months anniversary2104-05-28 (Wednesday)
100 months before2012-09-28 (Friday)
1000 months before1937-09-28 (Tuesday)
Anniversaries (years)
100 years anniversary2121-01-28 (Tuesday)
1000 years anniversary3021-01-28 (Sunday)
100 years before1921-01-28 (Friday)
1000 years before1021-01-28 (Sunday)

Some facts#

  • We may think, that adding or subtracting a few days (months, years) to (from) given date is a piece of cake. However, if we go deeper, we will find that there are many potential problems related to days arithmetic. Some months have 30, but other 31 days. Hey, but February has only 28 days! But, wait... once every four years February has 29 days. But which years are leap and which years are not? Argh! Maybe it will be easier to use Calculla?

What is the meaning of each calculator field ?#

  • Start date - it is date used as reference to all further calculations. For example, if you want to know what date will be 50 days after Easter set this field to Easter day and number of days to 50.
  • Number of days/months/years to add/subtract - this is a number of days (months, years), which will be added (and subtracted) from your reference date set in "start date" field.
  • Don't include (Saturdays/Sundays/public holidays) - use this fields to exclude selected days from calculations. For example you can use this option if you want to count next 20 working days from today. In this case you should exclude all non-working days i.e.: Saturdays, Sundays and public holidays. This option is applied when shifting days only i.e. it doesn't affect result of adding/subtracing months or years.
  • Your region - this option is used only, when holidays exclusion is enabled (see "Don't include" field). Based on this field, Calculla will adjust list of known holidays to place where you live.

See also#

  • If you are interested in this page, check our other calculators related to time:
    • Time: Date and time formats - date conversion between different formats and according to different calendars in the world,
    • Time units - converter of different time units e.g. hours to minutes or vice versa,
    • Add or subtract days/months/years to date - check what day it will be for the number of days, months or years you have chosen,
    • Work time - check how many hours or working days fall on selected period,
    • Dates difference - check how much time has passed the dates you selected,
    • Sleep time - check how many hours, days, years etc. you spent sleeping,
    • Life time - check exactly how many hours or days of life are behind you,
    • Time to holidays - check how much time is left until the next period off from work or school,
    • Time to new year - check how much time is left until the end of the current year,
    • State pension age - check how much time you still need to work to get the right to retirement.

Tags and links to this website#

What tags this calculator has#


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Links to external sites (leaving Calculla?)#

Ancient version of this site - links#

In December 2016 the Calculla website has been republished using new technologies and all calculators have been rewritten. Old version of the Calculla is still available through this link: We left the version 1 of Calculla untouched for archival purposes.
Direct link to the old version:
"Calculla v1" version of this calculator
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