Widely used Linux file systems like ext4 and XFS have a time stamp accuracy of one nanosecond, which can be seen using stat or ls -l --full-time. Even NTFS (the file system of Windows) has 100-nanosecond granularity, but was developed before ext4, and UDF (Universal Disk Format) 1 microsecond.
What are the practical uses of such time stamps?
Something I can think of: it can be used to measure the speed of file creations. For example, here is an excerpt from stat:
Code:
File: example.tar
Size: 146944 Blocks: 288 IO Block: 4096 regular file
[...]
Access: 2025-06-23 12:52:20.649459751 +0200
Modify: 2025-06-23 12:52:20.653459794 +0200
Change: 2025-06-23 12:52:20.653459794 +0200
Birth: 2025-06-23 12:52:20.649459751 +0200
This shows it took 4 milliseconds to create that file.
What are some other uses for this? It seems the clocks in many computers aren't even that accurate.
What are the uses for nanosecond time stamps?
