How do you calculate the time between two dates?

Subtract the start date and time from the end date and time. The result is the elapsed duration, which can then be expressed in seconds, minutes, hours, days or any other time unit. This page's calculator does that automatically once you enter both dates.

How many seconds are in a minute, hour, and day?

There are 60 seconds in a minute, 3,600 seconds in an hour, and 86,400 seconds in a day.

How many hours are in a week?

There are 168 hours in a week, since a week has 7 days and each day has 24 hours.

How do I convert days to hours?

Multiply the number of days by 24. For example, 3 days equals 72 hours.

How many days are in a month?

A calendar month has 28 to 31 days depending on which month it is. For conversion purposes, this calculator uses the average length of a month, about 30.44 days, based on the average Gregorian calendar year.

How many days are in a year?

A common year has 365 days and a leap year has 366. This calculator uses the average Gregorian calendar year of about 365.2425 days, which accounts for leap years over a long span.

Why is a month or year shown as a decimal number of days?

Months and years don't have a single fixed length in days, so converters use an average value. This calculator uses roughly 30.44 days per month and 365.2425 days per year.

How do I calculate a countdown to a future date?

Subtract the current date and time from the target date and time. This calculator does this live using the current time on your device, so the result updates each time you open the page.

How do I add up hours, minutes and seconds into a total?

Convert each part to the same unit and add them together, for example converting hours and minutes to seconds before summing. This calculator's Add Up a Duration mode does this automatically for days, hours, minutes and seconds.

How do I convert minutes to hours?

Divide the number of minutes by 60. For example, 150 minutes equals 2.5 hours.

Does this calculator account for time zones?

Dates and times are read using your device's local time zone and clock. If you're comparing dates across different time zones, convert them to the same time zone first for an accurate result.

Is this time converter free to use?

Yes, it is completely free, requires no registration, and runs entirely in your browser with no usage limits.

Responsive Advertisement

Time Conversion

3 calculators · 11 time units

Time Converter & Calculator

Find the time between two dates, count down to a date, or add up a duration's parts, then convert the result into seconds, minutes, hours, days, weeks, months, years and more — all calculated instantly in your browser.

3Calculator modes

11Time units

0msServer round-trips

Show result in

7d

Difference = 7d 0h 0m 0s

From

day

To

hour

24hour

hour = day × 24

Runs locally, no data sent Standard NIST/BIPM factors Free, no sign-up

How each calculation works

The logic behind each mode above, with a note on when to use it.

Quick conversion table

Common values for your selected units in the converter above, updated automatically.

Day	Hour

Time unit reference

What each unit means and what it's typically used to measure.

More converters from ConvertGPT

Working across other units too? These are the ones people pair with time most often.

Frequently asked questions

Straight answers to the questions people ask most about calculating and converting time.

All calculations and conversions run locally in your browser using your device's clock and standard NIST/BIPM conversion factors. No data is sent anywhere.

Convertgpt