HFS+ timestamp to date
For example, 3744921600 is Fri, Sep 02, 2022, 12:00:00 AM UTC, which is 2022-09-02T00:00:00.000Z in ISO 8601 and 1662076800 in Unix seconds.
Seconds since 1904-01-01T00:00:00, the HFS+ epoch, read as UTC. Unix time = HFS − 2082844800. Classic HFS stored the same count in local time, so a value from an old HFS volume may be off by that Mac's zone offset.
Detected: Mac HFS+ timestamp/t/3744921600
Your timezone
UTC · GMT+00:00 · UTC
Fri, Sep 02, 2022, 12:00:00 AM
Common formats
UTC
Fri, Sep 02, 2022, 12:00:00 AM
ISO 8601
2022-09-02T00:00:00.000Z
Unix (seconds)
1662076800
Unix (millis)
1662076800000
Relative
…
A Mac HFS+ timestamp counts seconds since midnight on 1 January 1904 as an unsigned 32-bit integer. It is the date format in HFS and HFS+ volume headers and catalog records, in AppleSingle and AppleDouble files, and in the classic Mac OS Date Time Utilities. A current value is about 3.7 billion, which is 2082844800 more than the Unix timestamp for the same moment. Paste one below to decode it.
Do it with the API
curl https://parsetime.dev/api/t/3744921600?format=hfsThe same conversion as JSON: no key, no signup, permissive CORS. Try this call or read the API docs.
Common questions
- Why does the HFS+ epoch start in 1904?
- 1904 was the first leap year of the 20th century, which let the original Macintosh clock routines count 1,461-day blocks without special-casing 1900. An unsigned 32-bit count from there runs out on 6 February 2040.
- How do I convert an HFS+ timestamp to Unix time?
- Subtract 2082844800, the number of seconds between 1 January 1904 and 1 January 1970. HFS+ 3744921600 is Unix 1662076800, midnight UTC on 2 September 2022.
- Is an HFS+ timestamp UTC or local time?
- HFS+ stores UTC, and this page decodes as UTC. The older classic HFS format stored the same count in the machine's local time with no zone recorded, so a date from an HFS volume or a pre-OS X file may be off by the zone offset of the Mac that wrote it. One exception survives in HFS+: the volume creation date stays in local time.
- Can I convert an HFS+ timestamp with the API?
- Yes: GET /api/t/3744921600?format=hfs returns the decoded date as JSON, with no key or signup.