Ihor Radchenko <yantar92@gmail.com> writes:
>
> I am unable to reproduce using built-in Org version of my own Emacs
> build (GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, cairo version
> 1.16.0) of 2022-01-29).
>
> Can you provide more details steps to reproduce starting from emacs
> -Q?

Sure.

Save "foobar.org" and "testcase_startup.el" into a directory. Start
emacs in that directory as "emacs -Q -l testcase_startup.el". When emacs
comes up, hit "a" to get agenda. 

"foobar.org" has one task scheduled for Sunday. When I write this, it is
Saturday. Task is displayed in agenda for Saturday.

Happy to investigate myself if you have suggestions of things I can look
at to track this down. 

(org-version)
"9.5.2"

(emacs-version)
"GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.20, cairo version 1.16.0)
 of 2022-03-09"

load-path:
("/usr/local/share/emacs/29.0.50/lisp"
"/usr/local/share/emacs/29.0.50/lisp/vc"
"/usr/local/share/emacs/29.0.50/lisp/url"
"/usr/local/share/emacs/29.0.50/lisp/textmodes"
"/usr/local/share/emacs/29.0.50/lisp/progmodes"
"/usr/local/share/emacs/29.0.50/lisp/play"
"/usr/local/share/emacs/29.0.50/lisp/org"
"/usr/local/share/emacs/29.0.50/lisp/nxml"
"/usr/local/share/emacs/29.0.50/lisp/net"
"/usr/local/share/emacs/29.0.50/lisp/mh-e"
"/usr/local/share/emacs/29.0.50/lisp/mail"
"/usr/local/share/emacs/29.0.50/lisp/leim"
"/usr/local/share/emacs/29.0.50/lisp/language"
"/usr/local/share/emacs/29.0.50/lisp/international"
"/usr/local/share/emacs/29.0.50/lisp/image"
"/usr/local/share/emacs/29.0.50/lisp/gnus"
"/usr/local/share/emacs/29.0.50/lisp/eshell"
"/usr/local/share/emacs/29.0.50/lisp/erc"
"/usr/local/share/emacs/29.0.50/lisp/emulation"
"/usr/local/share/emacs/29.0.50/lisp/emacs-lisp"
"/usr/local/share/emacs/29.0.50/lisp/cedet"
"/usr/local/share/emacs/29.0.50/lisp/calendar"
"/usr/local/share/emacs/29.0.50/lisp/calc"
"/usr/local/share/emacs/29.0.50/lisp/obsolete")