Currently, and I'm not sure if it applies to other days, the x100 (and DE) boost is not applying the servers that it says that it is currently applying on. I'm unsure if this is due to my timezone (from the USA),
I've attached images showing me on both the x100 servers (SG and DE), and that I am not getting the xp boost from either of them.
https://imgur.com/a/t15Kec5
Also note that the DE server doesn't have the boost that should have either.