Welcome!

The servers are actually only situated in one of two physical locations: Tokyo Japan, and Montreal Canada. Accordingly I presume server times would coincide with the location of where it is located. Having said that though, I've heard that several of the 'NA' servers (the ones located in Canada) actually have GMT (Greenwhich Mean Time) as their server time, as they're designated as 'EU' servers despite being located in Canada. But as I play on a Japanese server though I have no idea I'm sorry.