I don’t see anything that explicitly defined why they chose PCT, but I think it seems reasonable. PST means Pacific Standard Time, and PDT means Pacific Daylight Time. I could see PCT making Pacific Constant Time, or maybe Pacific Coordinated Time (in reference to UTC). Changing the middle character seems consistent with convention for timezone abbreviations.
I don’t see anything that explicitly defined why they chose PCT, but I think it seems reasonable. PST means Pacific Standard Time, and PDT means Pacific Daylight Time. I could see PCT making Pacific Constant Time, or maybe Pacific Coordinated Time (in reference to UTC). Changing the middle character seems consistent with convention for timezone abbreviations.