On 2/14/20 3:01 PM, Michael H Deckers wrote:
a TZ string may well specify that the "alternative" time is "permanent" (in the sense of being in force throughout the year), for instance with: EET-2/BST-1,J1/01:00,J365/24:00
Good point; I hadn't thought about the possibility of using negative DST to specify permanent daylight saving time. Unfortunately, this TZ setting does not work in recent GNU/Linux systems, like Fedora 31: $ TZ=EET-2BST-1,J1/01:00,J365/24:00 date -d@1577833199 Tue Dec 31 23:59:59 BST 2019 $ TZ=EET-2BST-1,J1/01:00,J365/24:00 date -d@1577833200 Wed Jan 1 01:00:00 EET 2020 Also, we know that many Java systems do not support negative DST. So even though the specific phrase quoted in the House of Lords document is incorrect, it's still the case that many practical systems don't support permanent DST.