How to Understand the Date and Time in Email Headers

Discover the location of the servers the email passed through

Businessman checking the time on his watch

When an email message is sent, it passes through several mail servers. Each one records the time and date in the email header. Look at the header to find out when the message was sent, as well as where and for how long it was delayed.

Date and Time Example

Here's an example of how the date and time information is presented in email headers:

Sat, 8 Jun 20

Here's what each of these snippets means:

  • Sat: The day of the week, using its three-letter abbreviation.
  • 8 Jun 2019: The date with a three-letter abbreviation for the month.
  • 11:45:15: The time in hours, minutes, and seconds, using a 24-hour clock.
  • -0500: The time zone offset, which is the difference between the time and Coordinated Universal Time (UTC) time. The value is preceded by a plus-sign if the time is ahead (east) of UTC, or a minus-sign if it's behind (west). In this example, the time is five hours west of UTC, which is the Eastern time zone in the U.S.

If the time zone offset value appears as zeroes only, the time zone is unknown.

Review Date and Time Information

Follow these steps to read and interpret the date and time found in an email header.

  1. Open the email message you want to review and look for lines beginning with Date and Received.

    If you don't see these fields, view the full email header.

  2. There may be many of these lines, so look carefully and note the different information in each area.

  3. Compare each area to see how much time passed between them.

Deciphering the Time Zones

The most difficult parts of the date and time to understand are the time and time zone offset. To convert the time to your time zone, use a time zone calculator.

Some email clients, such as Outlook, provide an option to adjust the settings to show the time based on your time zone.