We're really close to halfway from Y2K to the overflow of 32-bit time_t, but not *quite* there yet: $ TZ=UTC date --date=@$((($(date +%s --date="2000-01-01 00:00 UTC") + $((0x7fffffff))) / 2)) Thu Jan 10 01:37:03 UTC 2019 (I'm choosing to use Y2K in UTC.)