What is the ruling on someone who began fasting as an expiation for intercourse during Ramadan with the intention of fasting two calendar months (November and December), then learned that the expiation must be in lunar months, and what should he do now that he began fasting on November 1, 2007?

Whoever invalidates their fast by intentional sexual intercourse must offer expiation, which is to fast two consecutive months. The duration of the two months is calculated by the lunar calendar, and it may be 58, 59, or 60 days. If the one performing expiation fasts for 60 days, then they have completed their expiation correctly.