Add to Date accuracy and testing

Formula source

• The calculator adjusts the date object directly using calendar units. Days and weeks move by fixed counts, while months and years follow native date rollover behavior, so end-of-month results can shift into the following month depending on the starting date.

Test cases

Known limitations

• This page documents the checked-in calculator logic and does not certify results for every real-world edge case.
• Use the result as a planning estimate unless the calculator page states a stricter purpose.

Assumptions

• The calculator applies standard Gregorian calendar rules for month lengths and leap years.
• Month and year shifts follow native calendar rollover behavior when a target month has fewer days.
• This tool adds calendar time, not business days, so weekends and holidays remain included.

Unit handling

• Start Date accepts calendar dates.
• Operation accepts one of the configured options.
• Time Amount accepts numeric values.
• Unit accepts one of the configured options.

Rounding rules

• Number displays use up to 2 decimal places in the calculator UI.

Version history

Change log