There are no formal standards. Countries do as they please, when they please, with any amount of notice.  There are guidelines — please give us lots of notice of planned changes— but many countries do not follow them.


On Tue, Jan 29, 2019 at 23:46 Samah Kareem <samahkareem2012@gmail.com> wrote:
Hello All
I want to ask about references,  countries can change their time zone depending on, I want name of standards, guidelines if any.

Regards
Samah Kareem
--
Jonathan Leffler <jonathan.leffler@gmail.com>  #include <disclaimer.h>
Guardian of DBD::Informix - v2018.1031 - http://dbi.perl.org
"Blessed are we who can laugh at ourselves, for we shall never cease to be amused."