Was playing with my friend and decided to go to the moon, but we can not decrease the rate of 3 days. OMP does not allows speed up the time? No exist any other way? :facepalm:
Server admins can skip ahead the server time. If this happens, every client is free to accelerate above x2 on his own. However, you won't see each other during this synchronization period.
Going to the moon typically consists of launch, short Earth orbital phase, trans-lunar injection, coasting, mid-course correction, coasting, LOI, moon orbital phase. I'd suggest to plan your mission ahead with a server admin to skip the 2 time-consuming coasting phases. E.g. if your TLI is finished, the admin can skip the next 36 hours. You would then use normal Orbiter acceleration to fast-forward until you are in sync with the server clock again. Then do mid-course correction, followed by another skip of 36 hours.
There is a space-time bubble concept in planning that will give individual groups of clients the possibility to time-accelerate. The infrastructure is there, but no front-end yet. So you will have to wait for that, as my current focus is on persistence instead.