UTC Formats Generator
Generate valid UTC string formats for APIs, email headers, logs, and copy-ready output.
UTC Formats Generator
Generate and copy standard UTC formats from a single base UTC date.
ISO-8601 Z
2026-02-18T23:47:29Z
ISO-8601 +00:00
2026-02-18T23:47:29+00:00
RFC 3339
2026-02-18T23:47:29.025Z
RFC 2822
Wed, 18 Feb 2026 23:47:29 +0000
RFC 1123
Wed, 18 Feb 2026 23:47:29 GMT
RFC 850
Wednesday, 18-Feb-26 23:47:29 GMT
ATOM
2026-02-18T23:47:29+00:00
W3C
2026-02-18T23:47:29+00:00
Cookie
Wed, 18 Feb 2026 23:47:29 GMT
Unix epoch seconds
1771458449
Unix epoch milliseconds
1771458449025
YYYY-DD-MM HH:mm:ss
2026-18-02 23:47:29
YYYY-DD-MM hh:mm:ss A
2026-18-02 11:47:29 PM
DD-MM-YYYY HH:mm:ss
18-02-2026 23:47:29
MM-DD-YYYY HH:mm:ss
02-18-2026 23:47:29
ISO-8601 and RFC reference
| Format | Example | Typical use |
|---|---|---|
| ISO 8601 (Zulu) | 2026-02-18T14:25:36Z | Best default for APIs and storage. |
| ISO 8601 (offset) | 2026-02-18T14:25:36+00:00 | Equivalent UTC value with explicit offset. |
| RFC 3339 | 2026-02-18T14:25:36Z | Strict profile of ISO-8601 for JSON/web APIs. |
| RFC 2822 | Wed, 18 Feb 2026 14:25:36 +0000 | Common in email and legacy headers. |
Related UTC tools
Format guide
ISO-8601 Z vs RFC3339
ISO-8601 with a trailing Z and RFC3339 are both common for APIs. RFC3339 is effectively a profile of ISO-8601 and is broadly accepted in JSON and web services.
Epoch seconds vs milliseconds
Epoch seconds are 10-digit values for modern dates, while epoch milliseconds are usually 13 digits. Always confirm the expected unit before storing or parsing timestamps.
When to use custom formats
Use custom formats for human-readable exports and legacy systems. For machine-to-machine data, prefer ISO/RFC forms to avoid locale parsing issues.