You can join now, or do it any time in your own time.
I suggest any member who wants to join, or who does this any time in the future, first do 7 days of Pathology Liturgies to cleanse them, and open up better to the Cures Liturgies. If you start today for example, just do the Pathology Liturgies on your own and checkmark schedule participation in the Vultus Templorum "Spiritual Activities" room. If you have the time, you can do both the Pathologies and the Cures daily, I know there are members doing this, and it is very good to do.