TIME / CALENDAR
Date Calculator
Start from a date, add or subtract a calendar amount, and see the resulting date and weekday.
Set date inputs
Use a negative amount to move backward.
Resulting date
Your resulting date will appear here
Choose a base date, amount, and unit, then calculate.
Calendar offsets without manual rollover math
Days and weeks move by elapsed calendar days. Months and years preserve the day where possible, then clamp to the last valid day if the target month is shorter.
Use negative amounts
Enter -8 weeks to move backward, or 30 days to move forward. The same form supports both directions.
Month-end behavior
January 31 plus one month becomes February 28 or 29, depending on the year, rather than overflowing into March.
Frequently Asked Questions
Can I subtract time as well as add it?
Yes. Enter a negative amount to subtract days, weeks, months, or years from the base date.
Does it handle month-end rollovers?
Yes. Month and year changes are clamped to the last valid day of the resulting month when needed.
Can I add weeks directly?
Yes. Weeks are supported directly, so you do not need to convert them into days yourself.
Does it show the weekday?
Yes. The result includes the weekday of the resulting calendar date.
Does this store my dates?
No. The basic calculation runs in your browser and does not require stored data.