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RFC 2822 / HTTP Date Converter
Convert HTTP header and email-style dates to Unix timestamps and back.
RFC 2822 ⇄ Timestamp
Runs entirely in your browserType in either field — the other updates live.
Overview
What is RFC 2822 Date Format?
RFC 2822 defines the date format historically used in email headers. The same style — always in GMT — is used for HTTP headers like Date, Last-Modified, and Expires.
It's also exactly what JavaScript's Date.prototype.toUTCString() produces, making it a common sight in browser dev tools and server logs.
- Always expressed in GMT (UTC)
- Used in HTTP
Date,Last-Modified,Expiresheaders - Matches the legacy email
Date:header format - Human-readable by design, unlike a raw Unix timestamp
RFC 2822 Format
Tue, 01 Jul 2025 13:12:10 GMT
TueWeekday
01 Jul 2025Date
13:12:10Time
GMTZone
HTTP dates are always GMT — never a local offset.
Where You'll See This
Common Use Cases
HTTP
Date response header
HTTP Last-Modified header
HTTP Expires / cache headers
Cookie Expires attribute
Email Date: header
JavaScript toUTCString() output
FAQ
Frequently Asked Questions
RFC 2822 defines the date format historically used in email headers, formatted like
Tue, 01 Jul 2025 13:12:10 GMT. It's also the format returned by JavaScript's Date.toUTCString() and used in HTTP headers such as Date, Last-Modified, and Expires.
HTTP dates (defined in RFC 7231, formerly RFC 1123) use a stricter, fixed-width variant of the same style as RFC 2822 — always in GMT, always with a 4-digit year and zero-padded fields. In practice they look identical and both are commonly just called "HTTP date" or "RFC 2822 date."
Paste the header value — for example the string from a
Date, Last-Modified, or Expires response header — into this converter and the equivalent Unix timestamp appears instantly.
The HTTP specification predates widespread agreement on timestamp formats and chose a human-readable, unambiguous text format instead. It remains in HTTP for backward compatibility even though most modern APIs use Unix timestamps or ISO 8601 instead. Need that format? Use the ISO 8601 Converter.
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