file-birth-time · shipping · also btime, Birth time, File creation time

File birth time

File birth time (btime) is a filesystem timestamp recording file creation, distinct from modification time and inode change time.

On Linux, stat() does not return btime. statx() can return it as stx_btime where supported. Request STATX_BTIME and check that the returned stx_mask contains STATX_BTIME before interpreting the value; a successful call does not guarantee that every requested field was supplied. [2]

Availability depends on the kernel and filesystem. Do not substitute ctime for missing birth time. [1]

Relations

related
Inode, File modification time, Inode change time, File access time

Advantages

  • Separates recorded file creation from later content and inode-status changes.

Limitations

  • Not exposed by the traditional Linux stat() structure.
  • May be unavailable even when statx() succeeds.

Citations

  1. Linux man-pages: inode(7) (accessed 2026-10-21)
  2. Linux man-pages: statx(2), requested and returned fields (accessed 2026-10-21)

Further reading

  1. Hesela: interpreting file timestamps during rsync selection (accessed 2026-10-21)

JSON: /data/terms/file-birth-time.json

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Hesela team. File birth time. Hesela. 2026-10-21. https://hesela.dev/terms/file-birth-time/