In Vedic astrology, meaning "five attributes" of the day. They are:
Tithi - Ending Moment (EM) of elongation of the Moon, the lunar day , the angular relationship between Sun and Moon ( Apparent Moon minus Apparent Sun). One Tithi equals 12 degree difference between Moon and Sun.
Nakshatra - EM of asterism of the day, that is, the stellar mansion in which Moon is located for an observer at the center of the Earth. One Nakshatra equals 13 degrees:20 minutes. There are 27 Nakshatra in 360 degrees.
Yoga - EM of the angular relationship between Sun and Moon( Apparent Moon plus Apparent Sun). One Yoga equals 13 degrees:20 minutes. There are 27 Yogas in 360 degrees.
Karana - EM of half of a Tithi. One Karaṇa equals 6 degree difference between Moon and Sun.
Vara - weekday the seven weekdays.
We are all well aware of the concepts of "good timing" and "bad timing" and how at certain times everything seems to be flowing along smoothly, while at other moments things "just don't come together."
The calendar provides knowledge to understand such phenomena, so that one can take advantage of auspicious moments and avoid new undertakings when the creative forces are on the wane.