To calculate Rahu Kala, Gulika Kala and Yama Ghanta Kala we first consider the sunrise and the sunset time. We divide the time between sunrise and sunset into 8 equal parts. Considering the 7 planets (excluding Chaya Grahas - Rahu and Ketu), each planet is assigned to a slot and the remaining slot(8th Slot) is assigned to Rahu and this slot comes to be known as Rahu Kala.

Althought the time of sunrise and sunset varies according to place and season, for ease here we consider the sunrise and sunset time to be 6AM and 6PM respectively. So 12 hrs divided into 8 parts gives the duration of each part to be of 1.5 hrs.

The order starts from the ruling planet of the particular Vara (weekday). For eg if it’s a Sunday first part is always given to Sun since it lords Sunday and the second part is Moon, third is Mars, fourth Mercury, fifth Jupiter, sixth Venus, seventh Saturn and 8th portion will be blank and given to Rahu. Similarly this order of planets repeat for different weekdays starting from different planets. In case it’s a Thursday it starts from Jupiter, second part will be Venus, third will be Saturn and 4th will be Rahu. 5th, 6th, 7th and 8th will be Sun, Moon, Mars and Mercury respectively.

Yama Ghanta Kala: #

This is represented by planet Jupiter. For every day of the week, check the part that is owned by Jupiter and this will be the time frame occupied by Yama Ghanta. For eg on Wednesday Jupiter rules the 2nd part from 7.30 AM to 9 AM and that is the Yama Ghanta time and likewise on Friday it’ll be 4.30 PM to 6 PM which is the time represented by Jupiter. For easy reference, all of the Yama Ghanta time parts owned by Jupiter is coloured in Yellow in order to quickly spot it. Also some food for thought, if you closely check Jupiter rules all parts in different days except for the 6th part from 1.30 PM to 3 PM.

Gulika Kala: #

This is represented by planet Saturn. For every day of the week, check the part that is owned by Saturn and this will be the time frame occupied by Gulika. For eg on Thursday Saturn rules the 3rd part from 9 AM to 10.30 AM and that is the Gulika time and likewise on Saturday it’ll be 6 AM to 7.30 AM which is the time represented by Saturn. For easy reference, all of the Gulika time parts owned by Saturn is coloured in Blue for quick navigation. Also like Jupiter, Saturn rules all parts except for the 8th part spanning from 4.30 PM to 6 PM. P.S : For horoscope purposes, even sunset time will be taken and this also has a say in determining as to where Gulika will be placed in the vedic rasi chart.

Rahu Kala: #

This is represented by planet Rahu but the computation differs. Here time slots are put forth for each day of the week and Rahu kala is obtained based on the same. It must be remembered however that the first part of the day can never be Rahu kala. Also in addition to Rahu, other planets such as Sun, Moon and Mars also have a say in determining the Rahu kaal portion. They are marked in Red in the table to quickly catch attention. Listed below are the time parts assigned for Rahu kala in each of the days.