FWIW, the first test in the coreutils test suite covering the `date -r` case was added... 5 hours ago: https://github.com/coreutils/coreutils/blob/master/tests/

FWIW, the first test in the coreutils test suite covering the `date -r` case was added... 5 hours ago: https://github.com/coreutils/coreutils/blob/master/tests/date/reference.sh https://github.com/coreutils/coreutils/blob/master/tests/dat... I don't know what the code coverage of coreutils' test suite is, but my guess is that it's not spectacular.