How does it tell epoch seconds from milliseconds?

By digit count. 10-or-11-digit pure-integer input is treated as seconds (Unix timestamps are 10 digits through year 2286); 13-plus digits is milliseconds.

Why does ISO 8601 local include a timezone offset?

ISO 8601 requires an offset on local-time strings (`+09:00`, `-05:00`) so the instant is unambiguous. The UTC variant ends in `Z` and the offset is implicit.

The format HTTP defines for the `Date`, `Expires`, `Last-Modified`, `Set-Cookie` (Expires=) headers — `Mon, 02 Jun 2026 15:04:05 GMT`. Always UTC.

Why does the output differ across machines?

Locale (date / time string) and the local-timezone offset depend on your browser settings. The Unix epoch and ISO UTC values are the same everywhere.

Date Format Converter

Paste an ISO 8601 string, an RFC 2822 date, a Unix epoch (seconds or milliseconds — auto-detected by digit count), or any free-form date your browser can parse, and get the same instant rendered as ISO local / UTC, RFC 2822, HTTP `Date` (IMF-fixdate), SQL DATETIME, Unix seconds / milliseconds, locale string, date-only / time-only, and day-of-year. Leave the input empty to format "now".

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Date / time

Formats

ISO 8601 (local)2026-08-21T00:44:57.700+00:00
ISO 8601 (UTC)2026-08-21T00:44:57.700Z
RFC 2822Fri, 21 Aug 2026 00:44:57 +0000
HTTP / IMF-fixdateFri, 21 Aug 2026 00:44:57 GMT
SQL DATETIME (local)2026-08-21 00:44:57
SQL DATETIME (UTC)2026-08-21 00:44:57
Unix epoch (seconds)1787273097
Unix epoch (milliseconds)1787273097700
Locale (full)Fri Aug 21 2026 00:44:57 GMT+0000 (Coordinated Universal Time)
Locale (date)8/21/2026
Locale (time)12:44:57 AM
Date only2026-08-21
Time only00:44:57
Year / Day-of-year2026-233

How to use

Type or paste a date in any common format.
Read off the format you need; hit Copy to send it to the clipboard.
Click Now to clear the input and use the current time.

Frequently asked questions

How does it tell epoch seconds from milliseconds?: By digit count. 10-or-11-digit pure-integer input is treated as seconds (Unix timestamps are 10 digits through year 2286); 13-plus digits is milliseconds.
Why does ISO 8601 local include a timezone offset?: ISO 8601 requires an offset on local-time strings (`+09:00`, `-05:00`) so the instant is unambiguous. The UTC variant ends in `Z` and the offset is implicit.
What's IMF-fixdate?: The format HTTP defines for the `Date`, `Expires`, `Last-Modified`, `Set-Cookie` (Expires=) headers — `Mon, 02 Jun 2026 15:04:05 GMT`. Always UTC.
Why does the output differ across machines?: Locale (date / time string) and the local-timezone offset depend on your browser settings. The Unix epoch and ISO UTC values are the same everywhere.

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