Your bug report

#23299: 25.1.50; org-timestamp-change: Invalid time zone specification: (nil nil nil)

which was filed against the org-mode package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to 23299@debbugs.gnu.org.

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23299: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=23299
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