You can chat there at any time, but you'll have a much better chance of other people being there to chat with you if you come during one of the regularly scheduled chats. These chats are held in the #QueerByChoice chatroom on the DALNet servers on Sundays at:
1:00 p.m. Pacific Time
which equals 4:00 p.m. Eastern Time
which equals 9:00 p.m. British Time
which equals 1:30 a.m. the next day India Time
which equals 8:00 p.m. GMT/Universal Time Coordinated.
If you need any additional time zone conversions, you can convert them here.