Chandrashtama (Chandrashtama day) means a day when the Moon is transiting through the eight house (Ashtama Sthana) to your Rashi (Moon sign) as per Hindu Astrology. The entire two and half days of moon’s transit from the eighth sign is referred to as Chandrashtama days for the particular Rashi / native. This word is primarily formed by combining the two words Chandra and Ashta which mean Moon and Eighth respectively.
In specific considerations, the most critical part of Chandrashtama is the period of Moon’s transit through the specific Nakshatra. The considerable trouble is when the Moon travels through the 16th star from your Janma Nakshatra (the Star Constellation in which you were born).
According to astrological beliefs, one should avoid important works, medical treatments (surgeries), travel, shopping, high risk investments, new initiatives on Chandrashtama days.
As per Hindu Astrology, during Chandrashtama days, person’s mind is not in a balanced state to take proper decisions. The native needs to take more precaution and must be alert on these days. He/she can prevent many disputes, unpleasantness, tensions and a lot more misfortune during Chandrashtama.
Naturally, the Mano-Karaka Chandra is certainly ill-placed when in 8th house since it is a Natural debilitation house. And the result of this transit / placement may vary on Moon having benefic / malefic influences.