“I wonder how accurate is a couple’s astrology if the birth time is unknown? thanks!”
We don’t use houses in science-based Magi Astrology, 35 years of research has failed to confirm the validity or consistent accuracy of any of the MANY different house systems. So, birth time isn’t an issue because of houses.
The only important planet which we do use in couple’s astrology that moves quickly enough to make birth time an issue is Moon. My Love Reports http://bit.ly/Love-Stars are all designed to use linkages and clashes to and from Moon ONLY if that person has input a birth time and place. Moon is not used for any person whose birth time or birthplace is unknown.
Because science-based astrology places primary importance on Planetary Geometry, the reports are 95% accurate even if one or both birth times or birth places are unknown.
Have a great weekend!