For the PC version of the game, they post the start time / time zone for the EU, US and Asia regions, i.e. 17:00 PDT, 17:00 CEST, 17:00 KST.
However, the console version of the game does not have staggered regional start times. Seasons on console start at exactly the same time world-wide, and that start time matches the US server region’s start time, i.e. regardless of where in the world you are, if you’re playing on a console, the start time was 17:00 PDT.
The confusion comes from the fact that the blog gives the staggered time / time zones, based on region, and the console owners in EU assume the season will start at 17:00 CEST and post threads asking why the season hasn’t started, and that’s because it’s still hours away until 17:00 PDT.
This could all be avoided if the season start blogs included a single line saying that the console start time is the same world-wide, and it matches the US server start time.
The blogs used to specify this. I have no idea why they stopped doing so.