How to use this tool
Choose a start date, enter a whole number and select days or weeks. Positive values move forward, negative values move backward, and zero keeps the original date. Check the target date, weekday and expanded day formula before using the result for a reminder or event.
Rules and supported dates
Calendar days, including weekends and holidays. Adding zero returns the original date; this is not a working-day calculation.
Supported dates: 1900-01-01 to 2199-12-31
Worked example
Adding 4 weeks to 2024-01-01 adds 28 days and returns 2024-01-29. Entering -1 week moves back 7 days. Four weeks is not the same as one calendar month.
Common question
Can the tool skip weekends and public holidays?
No. It counts calendar days, including weekends and holidays, without local working-day adjustments. For the 30th day with the start counted as day 1, add 29 days. For 30 days after the start, add 30 days.