Historically, Amsterdam used a time zone 0h 19m 32.13s off GMT.  This was from about 1909 to 1937.
 

https://en.wikipedia.org/wiki/UTC%2B00:20


On Sat, Jul 30, 2022 at 12:41 Steve Allen via tz <tz@iana.org> wrote:

No, tz does not need subsecond precision, not for anyone, not in any
era. 
--
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."