Birth Chart Rectification and its  Importance :

Birth Chart Rectification is the process of taking apart a person’s birth chart based on known events in a person’s life so that the person’s birth time will be known.
We all know that in order to cast a complete natal chart, it requires an exact birth time. Though it is still okay to have only a person’s date of birth in casting an astrology chart, it is highly desirable to have on hand at least an approximate time of birth before attempting to interpret a person’s birth chart.
If the birth time is unknown or not recorded, astrologers sometimes will try to figure out the time of birth by studying the events in the person’s life and trying to harmonize their chronology with one of the possible charts for that day. This process is called birth chart rectification.
There are 5 Techniques on Birth Chart Rectification and they are as follows:
1.Employ Whole Sign Houses
Whole Sign Houses are more accurate in general practice and they are useful in the rectification process. The rectification process using whole sign houses becomes easy for it will be just a matter of determining the correct rising sign, then after that, all of the other houses fall into place. Since there is a striking difference between one rising sign and another, all of the planets move to different houses when the rising sign changes.
2.Understand the Concept of Benefic and Malefic Planets and Planetary Sect
These two concepts generate general thinking that the house placement of the malefic that is opposite to the sect of the chart will often point to the area of the native’s life in which they have some of their greatest challenges, hardships and even losses.
Otherwise, the house placement of the benefic that is of the sect in favor will often point towards the area of the native’s life in which things are the most fortunate, easy and stable.
Putting this in mind, you can look at each possible rising sign and compare where these two planets are located, and then compare this with the native’s chronology to see which placement seems to better reflect the most fortunate and unfortunate areas of the native’s life.
3.Compare the Ruler of the Ascendant in the Different Houses
This technique will work if the person has a particular time range already so that there can only be two or maybe three possible rising signs.
Remember that the house placement of the ruler of the ascendant often characterizes one of the major areas of life or topics that the native’s life is directed towards.  So if there are two possible rising signs in the chart that you are rectifying, then look to what house the ruler of the ascendant is in each, then ask the client which topic seems to be the more dominant one in their life. If one appear chiefly prominent, then you have narrowed down the correct rising sign.
4.Learn about Recent Outer Planet Transits
Learn about recent outer planet transits through the houses, particularly those of Saturn and Jupiter. We know that wherever Jupiter is transiting things are likely to expand, while wherever Saturn is transiting things are likely to contract.