I'm GMT-4, can do any time after 10pm my time for sure, other times depend on the day(I cannot do Saturday, except after 10)
I can do 10am to like 2pm sunday, which should be 4pm-10pm for you, does any time in there work for you?
On now as ANinjaDude, send message on SD when you want to battle, going to be on until 30 minutes after the agreed upon time.