Birth times
And your two birth times?
A four-minute difference in one birth time shifts that person's lines by about 1° of longitude, close to 110 km at the equator. A couple has two times, and two margins of error.
That is why both charts are recalculated with each time 30 and 15 minutes earlier and 15 and 30 minutes later, and each person's score combines the five times, with more weight on the time you gave. A place that only shines with one person's exact time loses strength. Each place carries, for each person, Meridian's stability sign: Stable, Moderate or Time-sensitive.
Meridian for Two needs both people's birth times. With approximate times, it can be done. If one of the times is unknown, I do not sell it: that person's lines would not be reliable. For the relationship, Two Skies works without a time.
The time is often on the full (long-form) birth certificate from the civil registry.