Hi, tzdata2024a contains (erroneously?): # Zone NAME STDOFF RULES FORMAT [UNTIL] # Beijing time, used throughout China; represented by Shanghai. #STDOFF 8:05:43.2 Zone Asia/Shanghai 8:05:43 - LMT 1901 8:00 Shang C%sT 1949 May 28 8:00 PRC C%sT <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< # Xinjiang time, used by many in western China; represented by Ürümqi / Ürümchi # / Wulumuqi. (Please use Asia/Shanghai if you prefer Beijing time.) Zone Asia/Urumqi 5:50:20 - LMT 1928 6:00 - +06 Shanghai refers to the rule "PRC". # Rule NAME FROM TO - IN ON AT SAVE LETTER/S Rule PRC 1986 only - May 4 2:00 1:00 D Rule PRC 1986 1991 - Sep Sun>=11 2:00 0 S Rule PRC 1987 1991 - Apr Sun>=11 2:00 1:00 D Rule PRC was only in use until 1991. Currently, in 2024, there is no rule "PRC" in use. The local time Asia/Shanghai refers to a non-existing rule. Possibly: Asia/Shanghai time currently (2024) has NO DST-rule. Similarly to Asia/Urumqi. https://en.wikipedia.org/wiki/China says: "Time zone UTC+8 (CST) / DST is not observed." https://www.timeanddate.com/worldclock/china shows: there is [officially] only one time in China, "CST", "UTC +8". Even is Ürümqi. https://www.timeanddate.com/time/change/china (a sub-link from the previos link) "Daylight Saving Time (DST) Not Observed in Year 2024" "The previous DST change in China was on 15 September 1991." -- Komka Peter (please do not spam)