I included a table of the time ranges supported as part of another series: https://lkml.org/lkml/2019/8/18/169. There had been some discussions with individual file system maintainers about what was the file system's intended range of supported timestamps. Eg: https://patchwork.kernel.org/patch/8308691/. I also added an xfs test(https://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git/tree/tests/generic/402) to test the ranges supported. But, since there was no way to query the kernel for ranges at that time, the ranges have to be plugged into xfstests for this to work on all filesystems. This does check for dates before 1970 if the range allows it. -Deepa
