Can I suggest a command to be implemented in the forums.
Some people don't tell their timezone modifier (mine being +2) and sometimes people add to their TZ instead of subtract. I suggest (if possible) a command where you type in the time you want to roll, and it comes up in the member looking at it in their Timezone.
E.G.
"Looking for # players to join RP system of choice at ((23:00 on Fridays))."
Lets say you are 2 hours ahead of the person sending this. where they have put "((23:00 on Fridays))", On your side you see "01:00 on Saturdays".
I feel it would solve a lot of calculations and confusion.