DatePlus can take dates in the standard {y,m,d,h,m,s} format of DateList:

DatePlus can take dates in any format supported by DateString:

If a date is given as {y,m,d}, DatePlus returns in the same form:

{y,m} is interpreted as the first day of the specified month:

{y} is interpreted as January 1 of the specified year:

Add 10 months to a date:

Add 40 weeks to a date:

Add 7 weeks and 2 days:

Add 1 year to a date list:

Add 1 month and 15 days to the specified date:

The increment can be specified using the quantity framework:

Add 2.45 days:

Subtract 4.6 hours:

Advance a date in the Jewish calendar:

Islamic years are shorter than Gregorian years:

Compare the dates 250 business days away in different countries:

Different markets within a country may have different holiday schedules:

By default, adding a month to May 31 will roll back to June 30:

Using Method"RollForward" will roll forward to the next valid date, July 1:

DatePlus[date,"Year"] will move forward 365 or 366 days, depending on the year:

Quantity[1,"Years"] is equivalent to Quantity[365,"Days"] in the Quantity framework:

Therefore Method"Continuous" will always add 365 days:

Compare the results of different arithmetic methods when adding a month to January 30, 2021:

Compare the results of different rolling methods for January 27 through February 1: