I am working with this Angels and I tell you, you do not need any particular day to start. You can start whenever.
However, GOM has this system and for results it is best to start on a Thursday and end on a Sunday!
If you are looking for something else to work with this Angels in the forum, check this thread
And follow what the OP does, if looking advance.
**If you still understand all, just do this: **
Just stare at the sigil for the Angel you selected, focus on the seal of the Angel, it is in colour red, when you feel a pull or flashing, pour your heart out, saying and thinking of your desire.
After that, say “It is done”. Thank the Angel.
This very effective, and surely you will get results. Do not worry about saying the psalms or contacting Arzel. However if this will make you more confident, you can do it.
Good luck!