On 9/28/21 5:38 PM, 大山俊成 via tz wrote:
I don't understand the meaning for line 3-5,20-22 of 2021b result. Is it correct ?
I think it's correct, unless you're seeing something I don't. 2021b zdump changed as noted in NEWS; look for "zdump -v now outputs timestamps at boundaries of what localtime and gmtime can represent". You can see the full documentation and source-code change here: https://github.com/eggert/tz/commit/ac07b446a3afaa4cb1ae11a91785a201c91f6351 zdump -v's new output differs from (and is intended to be more useful than) the old zdump -v output. For example, where the old zdump -v would have output the following, which doesn't correspond to any transition at all: Pacific/Honolulu -9223372036854689408 = NULL the new zdump -v outputs the following for the two transitions at (-67768040609740801) → (Thu Jan 1 00:00:00 -2147481748 UT), when gmtime starts succeeding, and at (Thu Jan 1 10:31:25 -2147481748 UT) → (Thu Jan 1 10:31:26 -2147481748 UT), when localtime starts succeeding: Pacific/Honolulu -67768040609740801 = NULL Pacific/Honolulu Thu Jan 1 00:00:00 -2147481748 UT = NULL Pacific/Honolulu Thu Jan 1 10:31:25 -2147481748 UT = NULL Pacific/Honolulu Thu Jan 1 10:31:26 -2147481748 UT = Thu Jan 1 00:00:00 -2147481748 LMT isdst=0 gmtoff=-37886