The following are the principal days in the Tibetan Lunar Calendar and the practices associated with those days:
8th Day- Medicine Buddha Practice
1st Qtr moon – White Tara Practice
10th Day – Guru Rinpoche Day / Shower of Blessings Tsog
15th Day – Amitabha Practice
Full Moon – Practitioner renews their vows and precepts. A time to reaffirm and make confession. So Jong for the Ordained
2nd Qtr Moon – Green Tara Practice
25th Day – Dakini Day, Tsog Feast
29th Day – Dharma Protector Day
30th Day – Shakyamuni Buddha Practice
New Moon – Practitioner renews their vows and precepts. A time to reaffirm and make confession. So Jong for the Ordained.
“From the Vajrayana or tantric point of view, the changes of the Sun and Mon produce a shift or change in the elements. While there is a shift on the more physical or gross level (the physical elements of the body), there is also a shift on a more subtle level – a shift in the wisdom mind (potential enlightened mind). This is sometimes referred to as the wind energy. This subtle system, which is not material or physical, is related to the mind. According to the Vajrayana practice, as we will gradually and eventually learn as we progress on the path, when all the different wind energies are channeled into what is known as the central or life channel, there is the experience of enlightened mind. That is how practitioners enter into the state of indestructible Samadhi and other meditative states. Related to that, on the occasion of the Full Moon, the 15th Moon, the 15th day, the right peripheral wind energy (also known as the white element) moves closest to the central channel. On the day of the New Moon, the wind energy of the left peripheral channel (also known as the red element) comes closest to the central channel. In general then, the lunar calendar is based on the motion of the Sun, Moon, and planets, and there is a definite relation of these cycles to the functioning of our subtle internal system.”
Above quote is from a teaching given by Ven. Khenpo Karthar Rinpoche