Planetary Hours in Vedic Astrology gives us a logical clue about How names of days of week were formed. Hora is one of the most important part of muhurta. Horas are determined on the basis of ‘srishtiyadi ahargana’ (number of terrestrial days passed from the day of creation) with the first Hora being ruled by Surya.
The 24th part of a Vara (day) is a known as Hora, English word, hour,” is derived from Hora. The Horas are ruled by the seven planets in order of the slowest moving planet to the fastest: Saturn, Jupiter, Mars, the Sun, Venus, Mercury, and the Moon. The first Hora of the Vara is ruled by the lord of the Vara, with the succeeding Horas following in the order given.
The 24th part of a Vara (day) is a known as Hora, English word, hour,” is derived from Hora. The Horas are ruled by the seven planets in order of the slowest moving planet to the fastest: Saturn, Jupiter, Mars, the Sun, Venus, Mercury, and the Moon. The first Hora of the Vara is ruled by the lord of the Vara, with the succeeding Horas following in the order given.
In Vedic system, the day is split into two periods, daytime and night time.
Day time – From Sunrise to sunset.
Night Time - Sunset to sunrise of the next day.