Nashta Jataka (Lost Horoscope) is one of subjects in classical Jyotish literature where using Prashna techniques the horoscope of the native is constructed, who has either lost the birth details or doesnt know their birth day and or exact time. But even if you have a fair awareness of the birth date and approximate time, having the precise time up to the second becomes important. When I first started learning Jyotish and going to Jyotishi’s for consultations they were blindly predicting with whatever time I gave, without giving any thought to the accuracy of the birth time. I started realizing that accurate time is required to predict accurately especially if the lagna degree is on the border of the rashis or if one wants to go into the divisional charts. The higher Amshas (divisionals) are very sensitive to the exact time up to the second.
As I found my Jyotish Guru Shri Deepanshi Giri ji and started learning the basics of Kala Chakra Dasha (KCD) from him, I started applying those principles to reverse engineer the life events onto KCD. As suggested by Deepanshi ji, if I used the SM Singh option on Jagannath Hora software and apply the KCD techniques, I was getting excellent results sometime up to the hour in my own chart. Although I must confess that I am completely oblivious to the actual calculations of KCD, but it works like a clock (literally) in some cases. Imagine the wheels of the clock machinery behind it to be the dasha periods on the KCD. The biggest wheel is the Maha Dasha, the next smaller wheel the Antar Dasha and so on.
Please find here an example of using KCD and other techniques to rectify the birth time. https://www.lunarastro.com/post/birth-time-rectification