How is the difference counted?

The total-days figure counts whole calendar days between the two dates. The years-months-days breakdown shows the same gap as a human-readable calendar duration.

Does the order of the dates matter?

No. If the end date is earlier than the start date the tool still shows the size of the gap and tells you the end date is before the start date.

Does the count include both the start and end dates?

It counts the days between them, not both endpoints. From 1 March to 8 March is 7 days. If you need an inclusive count (counting both the first and last day), add one to the total.

Why does the same gap show different "days" in the months breakdown?

The years-months-days view borrows the length of the relevant calendar month when the end day is earlier than the start day, so a gap that crosses February will borrow 28 or 29 days while one crossing a 31-day month borrows 31. The total-days figure is unaffected.

How do I count the number of weeks between two dates?

The tool divides the total days by 7 and rounds down to show complete weeks. A 100-day gap is 14 complete weeks (98 days) with 2 days left over.

Can it calculate a date difference across leap years?

Yes. The total is the exact number of calendar days, so any 29 February that falls within the range is automatically included.

Is any date data uploaded?

No — every calculation runs entirely in your browser and nothing is ever uploaded or stored.

Date Difference Calculator

Date difference calculator

Find exactly how far apart two dates are — for counting down to a deadline, working out a notice period, tracking a project span, or settling how long ago something happened. Enter a start date and an end date and the calculator shows the gap as a total number of days, weeks and hours, plus an exact years-months-days breakdown.

How it works

Both dates are normalised to midnight so partial days don’t distort the count. The total days is the millisecond gap divided by the milliseconds in a day, rounded to the nearest whole day; weeks are that figure divided by 7 (rounded down) and hours are days × 24. The calendar breakdown subtracts year, month and day separately, borrowing the length of the previous month when the day count would go negative and carrying down a month when needed. The order of the two dates never matters — the tool measures the gap from the earlier to the later date and simply tells you whether the end date falls before or after the start date.

Example

From 1 January 2026 to 30 May 2026 is 149 days, which is 21 complete weeks (plus 2 days) and 3,576 hours, or a calendar gap of 0 years, 4 months, 29 days.

Field	Value for 1 Jan → 30 May 2026
Calendar difference	0 yr 4 mo 29 d
Total days	149
Total weeks	21
Total hours	3,576

Everything runs entirely in your browser — nothing is uploaded.