Email Date checker
Paste the Date line of an email, or its full headers. You get the date in UTC and your time, and a check against the email standard and the clock.
Result
Example: paste your own Date line or full headers above.
Checks
3 passed- PassSyntax
Valid RFC 5322 date.
- PassWeekday
Friday matches the date.
- PassZone
+0000 is a real offset.
The check against the current time appears once the page has loaded.
Date
- As written
- Fri, 09 Oct 2026 14:30:00 +0000
- UTC
- 2026-10-09T14:30:00Z
- Sender's clock
- Friday 9 October 2026, 14:30:00 (+0000)
- Unix time
- 1791556200
- Written correctly
- Fri, 09 Oct 2026 14:30:00 +0000
How it works
Every email has a Date header: the time the sender says the message was written. RFC 5322 (the email format standard) fixes its form: Fri, 09 Oct 2026 14:30:00 +0000. That's an optional weekday, the day, a three-letter month, a four-digit year, the time and the offset from UTC.
Older mail used shorter forms: two-digit years, zone names like EST, and single military letters. Receivers must still read them, but senders mustn't write them. Military letters were defined with the wrong sign long ago, so they count as -0000, which means "the time is UTC, the sender's zone is unknown".
A Date in the future or far in the past is a spam signal, and it sorts the message to the wrong place in the inbox. It usually means the sending server's clock is wrong, or its time zone is set wrong. Keep servers in sync with NTP and let a date library write the header.
Each server that handles a message adds a Received header with its own time. The top one is the last server. Comparing it with the Date shows how long delivery took. For the whole path, hop by hop, use the header analyzer. To convert a single date, try the timestamp decoder.