I have ran a few tests on Ubuntu 16.04, 18.04, 18.10, and 19.04 (all X86_64):
16.04: root@u1604:~# date +%-Y -d '- 2010 years' 9 root@u1604:~# date --version date (GNU coreutils) 8.25 Copyright (C) 2016 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by David MacKenzie. 18.04: root@bionic:~# date +%-Y -d '- 2010 years' 9 root@bionic:~# date --version date (GNU coreutils) 8.28 Copyright (C) 2017 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by David MacKenzie. 18.10: root@u1810:~# date +%-Y -d '- 2010 years' 9 root@u1810:~# date --version date (GNU coreutils) 8.28 Copyright (C) 2017 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by David MacKenzie. 19.04: cerdea@piatam:/data/buildd/coreutils$ date +%-Y -d '- 2010 years' date: invalid date ‘- 2010 years’ 1 cerdea@piatam:/data/buildd/coreutils$ date --version date (GNU coreutils) 8.30 Copyright (C) 2018 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by David MacKenzie. Interestingly, it is also failing on git head: 130 cerdea@piatam:/data/buildd/coreutils$ src/date +%-Y -d '- 2010 years' src/date: invalid date ‘- 2010 years’ 1 cerdea@piatam:/data/buildd/coreutils$ src/date --version date (GNU coreutils) 8.31.12-6d78a Copyright (C) 2019 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Written by David MacKenzie. On Mon, Apr 15, 2019 at 12:16 PM O. Emmerson <oemmer...@gmx.com> wrote: > > $ file /bin/date > /bin/date: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), > dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for > GNU/Linux 3.2.0, BuildID[sha1]=26fa7f6c43c354d8c5647ebf946255a2b8e3c53d, > stripped > > > > -- ..hggdh..
