Convert Excel Time To Decimal Seconds

Explanation

In the Excel time system, one 24-hour day is equal to 1. This means times and hours are fractional values of 1, as shown in the table below:

Because each hour can be represented as 1/24, you can convert an Excel time into decimal hours by multiplying the value by 24, convert to decimal minutes by multiplying the value by 1440 (24 * 60) , and convert to seconds by multiplying by 86400 (24 * 60 * 60).

With the time value 6:00 cell A1, you can visualize the conversion like this:

=A1*(24*60*60)
=(6/24)*86400
=0.25*86400
=21,600

The Excel time 6:00 converts to 21,600 seconds.

Format result as number

When you multiply a time value by 86400, Excel may automatically format the result using a time format like h:mm, which will display the value incorrectly. To display the result as a regular number, apply the General or Number format .

Explanation

The Unix time stamp tracks time as a running count of seconds. The count begins at the “Unix Epoch” on January 1st, 1970, so a Unix time stamp is simply the total seconds between any given date and the Unix Epoch. Since a day contains 86400 seconds (24 hours x 60 minutes x 60 seconds), conversion to Excel time can be done by subtracting the date value for the Unix Epoch and multiplying days by 86400.

In the example shown, the formula first subtracts the date value for January 1, 1970 from the date value in B5 to get the number of days between the dates, then multiplies the result by 85400 to convert to a Unix time stamp. The formula evaluates like this:

=(B5-DATE(1970,1,1))*86400
=(43374-25569)*86400
=1538352000

How Excel tracks dates and time

The Excel date system starts on January 1, 1900 and counts forward. The table below shows the numeric values associated with a few random dates:

Notice the last date includes a time as well. Since one day equals 1, and one day equals 24 hours, time in Excel can represented as fractional values of 1, as shown in the table below. In order to see the value displayed as a time, a time format needs to be applied.