Hi, After a recent report of incorrect daylight saving time handling in agenda: Ignacio Casso [BUG] org-agenda thinks timestamps after 23:00 correspond to the next day Tue, 29 Mar 2022 15:09:10 +0200 https://list.orgmode.org/PAXPR06MB7760238F410CBE3203F78EE0C61E9@PAXPR06MB7760.eurprd06.prod.outlook.com I tried to create a compatibility helper that will use currently recommended way to call `encode-time' with single list argument for Emacs-27 and newer, but use the only available call style as separated arguments for older Emacs versions. From my point of view - it should work at the compile or load time to minimize runtime performance impact, - since both ways to call `encode-time' are necessary (in a half of cases a list returned by `decode-time' is available, in other cases timestamps are assembled from scratch, none is preferred), it should be convenient in both cases, - it should allow Org to work even if support of multiple `encode-time' arguments will be removed from Emacs. Paul Eggert proposed org-encode-time-1 defsubst/defun https://debbugs.gnu.org/cgi/bugreport.cgi?bug=54764#10 My patch requires more changes since the macro is just defined but not actually used. It does not fix the problem with "no DST" flag returned by some function in Org. I can prepare next patches, but I think it should be decided at first which approach should be accepted by Org Mode: - org-encode-time accepting both list or separate arguments - mix of `encode-time' with multiple arguments and org-encode-time-1 for lists.