erc-autojoin-delay

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

30

Documentation:
Number of seconds to wait before attempting to autojoin channels.
This only takes effect if `erc-autojoin-timing' is `ident'.
If NickServ identification occurs before this delay expires, ERC
autojoins immediately at that time.

You can customize this variable.

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