Added in 1.8.3
/sleep <N> <command>
Execute a command after N seconds, can be used to delay channel joins while waiting for NickServ Auth.
<N> - Seconds to delay.
<command> - Command to execute after delay. (Must start with a /)
;Delay 5 seconds, then join #channel1 and #channel2 /sleep 5 /join #channel1,#channel2