Time Zone Date and Time Calculator
This powerful all-in-one calculator provides time zone, time and date calculation functions. You can choose any operation you need, such as interval, weekday, date difference, timestamp, time zone, week number, etc. Enter the values in the fields and click Calculate.
Saturday, October 4, 2025, 08:32:00 PM +00:00
How to Use the Calculator
This tool offers multiple functions. Here's what each operation does:
- Add / Subtract Interval: Adds or subtracts a specific duration from the start date. Use ISO 8601 format (e.g.,
P10D for 10 days).
- Date Difference: Calculates the exact time between two dates.
- Get Weekday: Shows the day of the week for a date.
- Convert Timezone: Converts a date and time from your timezone to a target timezone.
- Get Week Number: Displays the ISO-8601 week number of the year.
- Days in Month: Shows how many days are in the month of a date.
- Check Leap Year: Tells you if the year of a date is a leap year.
How to Use Date Difference Calculator?
Follow the steps below to use Date Difference:
- Select the Date Difference option from the dropdown menu
- Choose time zone
- The start date and time is selected, but you can change it
- Select the end date and the exact time for the period
- Click the calculate button to get results in years, months, weeks, days, hours and in seconds
What is Day of the Week Calculator?
When you choose the Day of Week option, you are looking for the day of the week on any selected specific date. The date is up to you and you can choose any date using the date picker.
What is Week Number?
This is also the same, select from the dropdown menu and enter a date to know the week number of that year. For example, if you select the date August 21, 2025 and the time 16:30 (4:30 pm), the number of week will be 34 of 2025.