erc-autojoin-timing

erc-autojoin-timing is a variable defined in `erc-join.el'.
Its value is

connect

Documentation:
When ERC should attempt to autojoin a channel.
If the value is `connect', autojoin immediately on connecting.
If the value is `ident', autojoin after successful NickServ
identification, or after `erc-autojoin-delay' seconds.
Any other value means the same as `connect'.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.1 of Emacs.