First of all, to get us all on the same page: there is a tradition in the Ashtanga Yoga method of taking rest on moon days (full moon or new moon, which each occur once a month) instead of practicing asana.

This is based on the schedule of practicing six days a week, and having a consistent day of rest (typically Saturday, though you could structure a six-day-a-week practice with any consistent day off). So, a “daily practice” with these guidelines might mean you practice five days one week (when there’s a moon day in addition to your usual rest day) and six days the next week (no moon day), and so on.