Tula, the scale
Tula is the scale. Venus rules it. Agreements, a partner, and the attempt to weigh two sides.
The scale is a picture of weighing, and it has been flattened into a picture of people who cannot decide. Deciding slowly is sometimes the point of a partnership. Venus rules Tula, and the seventh sign of the natural order is this one, so marriage and the other person are the significations students memorise first.
A Tula lagna does not predict a wedding date. The wedding date is a muhurtham problem, solved from the panchang of a future day, sometimes with reference to the charts of two people. Mixing those two jobs, the natal chart and the electional day, is how apps end up promising a spouse in a month.
We keep the jobs apart. The chart page draws the sky of a birth. The today page scores a day. Neither page owes you a person.