Ketu Method - For timing the marriage.
This method is used by some old astrologers to find out quickly the year of marriage. It's easy to apply and gives correct results most of the time.
How to apply
Note the rashi lord of Ketu in the birth chart.
Note the lord of 7th house in birth chart.
The counting starts from rashi lord of Ketu by 1 year for one house.
When the progression is on 7th house lord, marriage happens in that year. I have seen sometimes if the progression is 7th from the 7th lord, marriage has happened in that year.
Although this method gives quick results, the final conclusion should be drawn after looking at the dasha and other parameters. There is some refinement required in this method. For example, what do we do when the rashi lord of Ketu is retrograde.
Example
Consider an Aries lagna chart. Ketu is in cancer. Rashi lord of Ketu, Moon is in Virgo. 7th lord Venus is in 9th house.
Counting starts from Moon. The progression on Venus is on the 28th year, so marriage should happen on the 28th year of age.
Sometimes, I have seen the progression in the 7th house from the 7th Lord, has also given marriage in that particular year.