Date difference
Pick two dates. We'll do the calendar math — leap years, varying month lengths, all of it.
Y/M/D vs total-days
The years/months/days breakdown rounds down at every level (whole years first, then whole months, then days). The total-days counter sums everything as straight calendar days. They'll often disagree by 1–2 days because of how leap years land — both are correct, they answer slightly different questions.
Frequently asked questions
How do leap years affect date difference?
Leap years add an extra day (Feb 29) every four years (with century-year exceptions). The calculator handles this automatically — total days will be one higher across each leap day in the range.
Why do years/months/days and total days sometimes disagree?
The years/months/days breakdown rounds down at each level using calendar rules; total days is a straight day count. Both are correct — they answer slightly different questions.