create a notice to be posted to chat every X seconds:
!notices add [secs] [command]
Notices will be handled intelligently and ones created with the same interval will be rotated through. For example:
!notices add 300 !command1 !notices add 300 !command2 !notices add 600 !command3
will result in one command being posted to chat every five minutes, in the following order:
!command1 !command3 !command2 !command3 !command1 !command3
!command3 is posted every ten minutes, and !command1/!command2 are alternated between.