What is the starting point for the waiting period (Iddah) for women from whom a man separates after electing four?

Primary text

The waiting period for the women who were separated from commences from the moment of the man's election of the four. This is because the bond with them is severed (ban) by the election itself. An alternative view suggests the waiting period begins from the time of the man's conversion (Islam), as their bond was established through his Islam, and the election merely clarifies that point.