What is the exact number of seconds between two dates and times? The *Seconds Between Dates Calculator* is your go-to tool. This calculator is perfect for precise time interval measurements for project timelines, event planning, or just satisfying your curiosity.

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## How to use the seconds between dates calculator

Using this calculator is straightforward. Here’s how to find out the exact number of seconds between two dates and times:

Input the start date and time in the respective fields.*Enter Start Date and Time*:Input the end date and time in the respective fields.*Enter End Date and Time*:Choose the time zone for the calculation. (The tool will try to guess your current time zone.)*Select Time Zone*:Hit the*Calculate*:**Calculate**button to get the precise number of seconds between the two dates and times.

The results will include the number of seconds between the specified dates and times.

### Handling special time conditions: Daylight Saving Time, Leap Seconds, and Leap Years

#### Daylight Saving Time Adjustments

When calculating the seconds between dates that cross the Daylight Saving Time (DST) changeover, the calculator automatically compensates for the hour gained or lost.

#### Leap Seconds and Leap Years Consideration

The Seconds Between Dates Calculator incorporates adjustments for leap seconds and leap years, ensuring every second is accounted for.

*Leap seconds* are added to or subtracted from Coordinated Universal Time (UTC) to synchronize clocks with the Earth's slowing rotation. If your time span includes a leap second, rest assured it's included.

Leap years, which add an extra day to February, are also considered in the calculations. This feature ensures that any period including February 29 is accurately measured.

### Who benefits from using this tool?

Anyone who needs to calculate the exact number of seconds between two dates and times will find this calculator handy. It's particularly useful for:

- Project managers tracking project timelines.
- Event planners scheduling events down to the second.
- Researchers analyzing time intervals in studies.

For related tools, check out our Seconds Ago Calculator and Seconds From Now Calculator to calculate past and future times with precision. Or, try the seconds between clock times calculator.