Date Calculator
Calculate the difference between two dates in days, weeks, months, and years. Or add and subtract days, weeks, months, and years from any date to find a future or past date.
Date Calculator
Calculate the difference between two dates or add and subtract days, weeks, months, and years from any date. Results show the span in days, weeks, months, and years simultaneously - useful for project planning, age calculations, countdowns, and deadline tracking.
Frequently Asked Questions
How is the month difference calculated?
Months are counted by comparing the year and month components of both dates, so a difference from January 31 to March 1 counts as 2 months regardless of day count.
Does it handle leap years?
Yes. Day-based arithmetic uses millisecond timestamps which automatically account for leap years. Adding one year to February 29 on a leap year produces February 28 on the following non-leap year.
What does a negative day difference mean?
A negative value means the end date is before the start date. The absolute value and the "before/after" label make the direction explicit.