How does the Date Duration Calculator count months and days?

It gives a calendar-aware breakdown: whole years, then whole months, then leftover days. When the end day-of-month is smaller than the start's, it borrows the earlier month's length, so a span like Jan 31 to Mar 1 reads as 1 month and 1 day.

What counts as a business day in the result?

Any Monday through Friday in the range counts as one business day; Saturdays and Sundays are excluded. The tool does not know regional public holidays, so deduct any weekday holidays for your country separately.

Can I include start and end times, not just dates?

Yes. Each side has an optional time field. Leave both blank for whole-day math, or enter times to get exact total hours and minutes and a to-the-minute years/months/days span.

What happens if I put the later date first?

The calculator handles either order. It always reports the span between the two dates and notes when the range is reversed. Use the Swap button to flip the From and To fields into chronological order.

Why is a one-year span sometimes 365 days and sometimes 366?

Leap years add February 29. A span crossing a leap day, such as 2020-01-01 to 2021-01-01, is 366 days, while a common-year span like 2021-01-01 to 2022-01-01 is 365 days — both still read as exactly 1 year.

Are the dates I enter uploaded anywhere?

No. The Date Duration Calculator runs entirely in your browser and computes everything on your device. The dates and times you type never leave your machine and are not sent to ArrayKit.

Date Duration Calculator

Find the exact time between two dates — years, months, weeks, days, hours, and business days — in your browser. The dates you enter stay on your device.

The Date Duration Calculator runs entirely in your browser. The dates and times you enter are used only for the on-device calculation and never leave your machine or reach ArrayKit.

Open the Unix Timestamp Converter

About Date Duration Calculator

The Date Duration Calculator measures the exact span between two dates and, if you need it, two times. Enter a start and an end date and it returns a full years, months, and days breakdown alongside total days, weeks plus leftover days, months plus days, total hours and minutes, and the number of business days (Mon–Fri) in between. It handles either order — put the later date first and it still reports the span, flagging that the range is reversed. Add optional times to get down-to-the-minute results, or leave them blank for whole-day math. It is built for planning deadlines, counting notice periods, checking contract or age spans, and answering "how many working days until launch?" Everything is calculated on your device — the dates you enter never leave your browser.

Features

Full years, months, and days breakdown between the two dates
Total days, total weeks, and weeks plus leftover days
Total hours and total minutes for down-to-the-clock spans
Business-day count that skips Saturdays and Sundays
Optional start and end times for minute-level precision
Handles reversed order and tells you when the end is before the start
One-click Swap to flip the two dates, plus a Today shortcut
Runs entirely in your browser with no dates sent anywhere

How to use the Date Duration Calculator

Pick a start date in the From field (add a time if you need one)
Pick an end date in the To field, or tap Today
Read the years / months / days summary and total-days figures
Check the Business days row for the Mon–Fri working-day count
Use Swap to reverse the two dates and recompute instantly

Example

Input

From: 2020-01-01
To:   2021-01-01

Output

1 year, 0 months, 0 days
Total days: 366  ·  Business days: 262

2020 is a leap year, so the span is 366 days — 262 of them weekdays.

Common errors & troubleshooting

The result shows one more or one fewer day than expected. — Duration counts full elapsed days. With times blank both dates sit at midnight; add the actual start and end times if you need the partial day included or excluded.
Business-day count looks off around a holiday. — The count skips only Saturdays and Sundays. Public holidays vary by country, so subtract any that fall on weekdays in your region yourself.
The end date is earlier than the start date. — That is fine — the calculator reports the span between them and marks the range as reversed. Use Swap if you want the fields in chronological order.
A month boundary like Jan 31 to Mar 1 reads oddly. — Months have different lengths, so the years/months/days view borrows the earlier month's length: Jan 31 to Mar 1 reads as 1 month, 1 day, which matches how most calendars count.

Frequently asked questions

How does the Date Duration Calculator count months and days?: It gives a calendar-aware breakdown: whole years, then whole months, then leftover days. When the end day-of-month is smaller than the start's, it borrows the earlier month's length, so a span like Jan 31 to Mar 1 reads as 1 month and 1 day.
What counts as a business day in the result?: Any Monday through Friday in the range counts as one business day; Saturdays and Sundays are excluded. The tool does not know regional public holidays, so deduct any weekday holidays for your country separately.
Can I include start and end times, not just dates?: Yes. Each side has an optional time field. Leave both blank for whole-day math, or enter times to get exact total hours and minutes and a to-the-minute years/months/days span.
What happens if I put the later date first?: The calculator handles either order. It always reports the span between the two dates and notes when the range is reversed. Use the Swap button to flip the From and To fields into chronological order.
Why is a one-year span sometimes 365 days and sometimes 366?: Leap years add February 29. A span crossing a leap day, such as 2020-01-01 to 2021-01-01, is 366 days, while a common-year span like 2021-01-01 to 2022-01-01 is 365 days — both still read as exactly 1 year.
Are the dates I enter uploaded anywhere?: No. The Date Duration Calculator runs entirely in your browser and computes everything on your device. The dates and times you type never leave your machine and are not sent to ArrayKit.

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