The rules are given below.
|Dhuma||Sun + 4 signs 13:20||-|
|Vyatipata||12 signs - Dhuma||-|
|Parivesha||Vyatipata + 6 signs||-|
|Chapa||12 signs - Parivesha||Other name: Indra Dhanus|
|Upaketu||Chapa + 16:40||Other name: Ketu|
Accordingly the night time (i.e. time from sunset to next sunrise) is divided into eight parts, and the first portion is assigned to the 5th lord of the weekday.
Each of these parts can be assigned to a Kala Vela. Default assignements are: the portion of the Sun ist Kala, Mars is the lord of Mrityu, Jupiter lords Yama Ghantaka, Mercury rules Ardha Prahara and Saturn rules Gulika. Moon and Venus have no Kala Vela portion. Some people say that Mandi is identical to Gulika, others say that Gulika lords the eight portion.
Moreover the portion of the rising part plays an important role: the exact point of the Kala Velas in the zodiac can be the beginning, the middle or the end of the corresponding portion. Most astrologers take the beginning of the parts as reference for calculation.
The zodiacal point of the Kala Velas is the ascending point at the time of the corresponding portion.
The rules are summarized in the table below.
|Name||Default Lord||Default Portion||Remark|
|Mandi||Saturn/Eight Portion||None||Middle of Saturn's portion, middle (or beginning) of 8th etc.|
The configuration has 3 parts: