There should be a regular pattern: banded octets on, say, Mondays (because only 8 people can enter each one, they need to be frequent), other banded types on first Friday of each month, open octets on Wednesdays, group of open tourneys on second Friday, and so on. Not so important with other tournaments because they can take a while to fill, but octets need a regular weekly schedule so that everyone gets a chance.
Alternatively, we should be able to book for tournaments that haven't yet been created - might be harder to organise though.