I recently conjured up a small script to find the newest files in a moderately sized filesystem (140GB / 53,000 files, compression=zstd) and it gave reasonable results… except for three files in widely scattered directories, all with identical timestamps in May 28, 2057. Specifically, from find -printf "%T@ %p":
2758271770.0000000000
Is this a special marker for ZFS? Time on this system has always been well regulated by NTP.
My guess is that this is a signed 32 bit -1 stuffed into a 64 bit time_t without sign extension. That is, the time you are seeing is probably 2^32-1 seconds after January 1, 1970. How it got that way is anyone’s guess. The file owner or root could set the timestamp with utimes() or similar.
Oops, that’s not it. That would be in 2106.
The hex value is 0xA46ABC5A, which doesn’t jump out at me as a common value.