The Gulikadi Group
This group consists of five subplanets. To calculate their position, the day (i.e., the time duration from sunrise to sunset) is divided into eight equal parts. The first part belongs to the lord of the day itself (e.g., the Sun for Sunday, the Moon for Monday, Mars for Tuesday, etc.). Subsequent parts belong to the remaining six planets. The eighth part is without a lord.
The part ruled by Saturn is called Gulika (or Mandi);
that ruled by Jupiter is called Yamakantaka,
the one ruled by Mars is called Mrityu,
the one falling under the Sun is called as Kaala or KaalaVela,
and the one ruled by Mercury is known as Ardhaprahara.
Now, let us discuss them in detail.