Time zones are set by the DOT, so any change like this likely requires federal action... https://www.transportation.gov/regulations/procedure-moving-area-one-t

Time zones are set by the DOT, so any change like this likely requires federal action... https://www.transportation.gov/regulations/procedure-moving-area-one-time-zone-another https://www.transportation.gov/regulations/procedure-moving-... Now, not respecting Daylight Savings Time is another matter entirely, and I believe that California could decide to be permanently in PST w/o the approval of the DOT. What they can't do is change the dates for DST or decide to always observe it (which would effectively end up creating a new time zone). https://www.transportation.gov/regulations/daylight-saving-time https://www.transportation.gov/regulations/daylight-saving-t...