This is the normal schedule they use so that nobody in any time zone can claim that it doesn't fill the whole "weekend".
Last one was clearly a last minute scramble to try to make people less mad about the XP changes, so they started it late.
Our last 2XP event was to help kick off the start of Llama-Rama. This weekend's 2XP event uses the same start and end days/times we've typically used in the past.