The following are the simple rules given in classical Vedic astrology to find out the results for any particular day. These are very useful.
First ascertain the result giving capabilities of the prevailing mahadasha. If mahadasha is found to be effective for benefice / malefic giving results then these results benefic / malefic occurs:
(1) In the weekdays ruled by mahadasha lord e.g. if the effective dasha going on is of Moon than one may gets its benefic / malefic results on Mondays. The same results should be applied for effective antardasha & pratyantardasha.
(2) The days ruled by the Nakshatras of mahadasha lord e.g. if the effective mahadasha going on is of Saturn than one may gets its benefic / malefic results on the days ruled by the Saturn’s Nakshatra such as Pushya, Anuradha & Uttarbhadrapad. The same results should be applied for effective antardasha & pratyantardasha.
(3) When Moon transits the exaltation sign of benefic effect giving dasha lord the good results of the mahadasha exist within its transit e.g. if the mahadasha of well disposed Sun is going on than its benefic results exists when Moon transits Mesh rashi i.e. the exaltation sign of Sun. Whatever has been said about this transit should equally applied to effective antardasha & pratyantardasha.
(4) When Moon transits over 3rd, 5th, 6th, 7th, 9th, 10th and 11th house with respect to benefic results giving mahadasha lord the result is good otherwise there will be adverse results. While in its mentioned benefic transit with respect to mahadasha lord this Moon represents certain house from Lagna and the benefic effect of that represented house will come to pass e.g. if benefic effect giving Dasha of Jupiter is going on and transits 11th house with respect to this mahadasha lord Jupiter representing 10th house from lagna then this benefic transit of Moon gives the benefic result of 10th house i.e. career. In this way the benefic & malefic results of any house in a horoscope are estimated. The same thing should be applied in case of effects giving antardasha & pratyantardasha.
Moon transits a sign of zodiac with about 2.25 so the results attributed to the transit of Moon in (3) and (4) comes to within a period of 2.25 days.
Irrespective of mahadasha / antardasha this Moon also gives benefice results while transiting through 1st, 3rd, 6th, 7th, 10th and 11th houses with respect to its natal position provided no planets except Mercury transit the corresponding Vedha places, i.e. 5th, 9th, 12th, 2nd, 4th & 8th.
In Varshphal, annual horoscope is cast to predict about a year, Month horoscope to predict about the month and Day horoscope to predict about a day. This is very wonderful scheme in Vedic astrology to predict about a year, month and a day.
The predictions about any day can be given on the basis of Vedic horary astrology i.e. prashan Kundli. Is someone puts a question concerning the benefic or malefic nature of a particular day then the position of Moon in the horoscopes cast at sunrise and sunset of that day is to be judged and if Moon is found to be well disposed in both the horoscopes then that day will be very good and the day concerned will be adverse if the positions of Moon found otherwise.
In my long experience in the field of astrology I have found aforesaid rules very general in nature and they are in the form of raw materials. Only research work along with experience is required to refine them. A person with deep knowledge of astrology can understand it.