First of all, this problem is far more common than you think. Birth-times, even when recorded on official certificates, are often inaccurate.
They tend to be rounded off to the nearest 5 or 10 minutes, even to the nearest quarter of an hour, unless someone attending the birth is doing careful time-keeping. It’s not that people are lazy – in the modern medical way of thinking, the moment of birth is of little significance.
Sometimes, it may be based on the memory of someone in the delivery room, or the time that the doctor or nurse fills out the certificate. In other cases, one has to rely on the memory of a parent, or something they were told when they were young, which may be off by a considerable amount.
This casual attitude toward accuracy makes the casting of correct birth horoscopes rather difficult. Although a difference of a few minutes may not matter in a birth-chart (if the person is born with the ascendant in the middle of a zodiac sign), in derived charts, such as Solar and Lunar Returns, the error that accumulates over time could eliminate their value as forecasting tools. Astrologers, over the centuries, developed methods of Rectifying, or correcting, the birth-chart. In India, this was called the method of finding Lost Horoscopes.
Rectification requires a study of major past events in order to adjust the “fitness” of the horoscope. This is absolutely crucial when working with Active Astrology; it would be unethical to make a Targeted Solar or Lunar Return based on an incorrect birth chart. The preliminary study is followed up by a set of “reverse-predictions.”
Once the rectified chart has been verified, you can be sure that your Solar and Lunar Returns will give accurate results, and that the actions you perform will enable you to reap the maximum rewards.