In Vedic Astrology , special importance is given on Muhurata . The ancient sages believed that any work commenced at a suitable and appropriate moment always yields favorable results.
The rule of selecting appropriate muhurata are applied even today. Before commencing any work, it is necessary to select the proper "Muhurata", so that obstacles are eliminated and success assured.
Whilst it is mandatory to select most auspicious day and time for important events like marriage , opening of company etc , it is important that we bear in mind the good and bad period of the day to improve our success rate in even normal things like starting of journey , starting of important discussions & meetings etc.
The most important period of the day is Rahu Kaal and it represents inauspicious period of the day. As per Hindu Astrology, Rahu Kaal occurs between sunrise and sunset for about one and half hours everyday. Rahu Kaal for each day in a week is different and is calculated basis sunrise and sunset time. No auspicious work is to be initiated or journey undertaken during this time since it will not yield a positive or constructive result. It is believed that Rahu Kaal will not affect the work, journey or trade already in progress however we should not sign any major documents or start a new enterprise in this period . The sale or purchase of any assets is also discouraged during Rahu Kaal. It is a very negative period to be shunned for all auspicious and beneficial activities. It is very religiously followed in Southern Part's of India.
Similarly there is the 'Gulika-kaal' (or simply 'Gulik') which is also a period of approximately 1 hour and 30 minutes duration every day of the week. This time duration is ruled by 'Shani' (Saturn). 'Gulik Kala' is considered a good period to undertake new projects.
Also there is Yamaganda Kaal for one and half hours during the day which is not considered good time for undertaking any project.
This time is calculated by dividing 'Dinamaan' into eight equal parts (each of approximately 1 hour 30 minutes). The 'Dinamaan' is the total duration of time between local sunrise and sunset on any given day. I am giving below the popularly known timings for these, for the different days of the week and these are indicative times considering notional sun rise at 6.00 am and notional sun set at 6.00 pm. Based on the actual sun rise and sun set time of the day, the Rahukala / Gulika Kala / Yamaganada kala timings have to be suitably corrected. (Sun rise and sun set times are not same for all days of the year even in the same place). This period will vary with different latitudes by a few minutes.
Rahu Kaal (Not Good )
Monday 7:30 – 9:00 Tuesday 15:00 – 16:30 Wednesday 12:00 – 13:30
Thursday 13:30 – 15:00 Friday 10:30 – 12:00 Saturday 9:00 – 10:30
Sunday 16:30 – 18:00
Gulika Kaal ( Good )
Monday 13:30 – 15:00 Tuesday 12:00 – 13:30 Wednesday 10:30 – 12:00
Thursday 9:00 – 10:30 Friday 7:30 – 9:00 Saturday 6:00 – 7:30
Sunday 15:00 – 16:30
Yamaganda kaal ( Not Good)
Monday 10:30 – 12:00 Tuesday 9:00 – 10:30 Wednesday 7:30 – 9:00
Thursday 6:00 – 7:30 Friday 15:00 – 16:30 Saturday 13:30 – 15:00
Sunday 12:00 – 13:30