If I remember correctly.....we take all fresh positions, adds etc in the next expiry contracts during the last 2-3 days. If nothing comes, we square off on the last day and take simultaneous position in the next cycle.(I dont personally wait even for a minnute during roll over...some do it to gain a price advantage, ie...sell the current contract at x and buy the next at x-y.).
Thats a personal rule though.....love to know a better way.
Rakesh