Date Difference Calculator
Days between two dates, plus a D-day countdown.
🔒 100% browser-based — your data never leaves your device.
About this tool
Pick two dates and instantly see the gap between them in days, weeks and calendar months — useful for project timelines, rental periods, visa windows, pregnancy weeks or anniversaries. If the second date is in the future, the tool doubles as a D-day countdown.
The count uses calendar dates, ignores time zones and daylight-saving quirks, and treats the two endpoints the way you would when counting on a calendar.
Frequently asked questions
Is the end date included in the count?
The main result counts nights between the dates (end minus start). The inclusive count, which adds one to include both endpoints, is shown alongside.
What does D-day mean?
A target date you are counting down to. D-7 means seven days remain; D+3 means three days have passed since the date.
Can I calculate weeks for pregnancy or projects?
Yes, the result includes full weeks plus leftover days, e.g. 45 days = 6 weeks 3 days.