PanchAnga Yogas

As per a member request, Today i have to post details of the Combination of certain yogas, namely Amirtha, Siddha, Marana Yogas as complied in many Panchanga / Almanac.  These yogas are taken into account while fixing an Auspicious Muhurtha.  These yogas contribute much to the auspicious making of an event by the Kartha, and fructifies the event or muhurtha.  The malevolance of the planet or Thithi is reduced, when an auspicious yoga is fixed for that Muhurtha.
Combination of certain thithi with vAra with NatcharAs and planetary elements forms Yogas Subha, Amirtha, Siddha, Amirtha-sidhathi yogas.  There are five categories of thithi :-

Nanda  : Pratipad,  Shasthi, Ekadasi
Bhadra : Dvitiya,   Saptami, Dvadasi
Jaya   : Tritiya,   Astami,  Trayodasi
Rikta  : Chaturthi, Navami,  Chaturdasi
Purna  : Panchami,  Dasami,  Purnima, Amavasya

The 5 categories of Tithis are governed by 5 elements of nature and when a tithi falls on a weekday governed by the same element as that of the tithi a very auspicious time is formed which goes by the name of Siddha Yoga.  Tithis and the Varas of the following constitute the siddha yoga:

Nanda  : Friday    :Venus   : Jala    Tattva
Bhadra : Wednesday :Mercury : Prithvi Tattva
Jaya   : Tuesday   :Mars    : Agni    Tattva
Rikta  : Saturday  :Saturn  : Vayu    Tattva
Purna  : Thursday  :Jupiter : Akash   Tattva

Amrita Siddhi Yoga:
This yoga is formed due to combination of weekday and a star.

Sunday  : Hasta
Monday  : Mrgashiras
Tuesday : Aswini
Mercury : Anuradha
Thursday: Pusya
Friday  : Revati
Saturday: Rohini

Eventhough the above is clear for Good yoga, following combination of star and a weekday should be avoided for certain auspicious muhurthas

For Marriage    : Thursday- Pushyami
Graha Pravesham : Tuesday - Aswini
Travelling      : Saturday- Rohini