Guild Wars 2

Knowing that earth is divided into multiple time-zones, I wonder the merit of giving every server a dedicated time in which annual and once-off events will start.

For example, if Anvil Rock is decided to always have events start at 9am PST, and each Server down the list starts 1 hour later, then players can shift to the servers that they think would suit their lifestyle and schedules.
Doing this won’t solve the problems for everyone or prevent all obstacles for people participating in events, but when it comes to Server selection players would have more information guiding them. This decision may also help players find more people in similar time zones playing at roughly the same time.

Of course it’s hard for Anet to decide how every event in the future will be released, but allowing players better opportunities to be on the right server ahead of time might increase participation quite a lot.

Not a bad idea. This way players can choose a server with the best timing for them.