Monday is ruled by the moon. Magical work planned for a Monday should involve aspects of the Goddess and any rites to honor her. In Wicca, the phases of the moon are revered as natural symbols of the different phases of womanhood. Spells and rituals invoking change are appropriate for a Monday.
The moon rules the tides, so spells involving water are also appropriate for this time. Think of purification and cleansing work that you may need to do. Even consecrating your chalice would be an appropriate work for a Monday. Meditate on the aspects of the Greek maiden huntress, Artemis, twin sister of Apollo, or on her Roman counterpart, Diana of the silver bow. The lunar energy will bless your work if you acknowledge it correctly.
—Judy Ann Olsen, A Witch’s Grimoire: Create Your Own Book of Shadows