Subject to Sale Addendum and Earnest Money

Question:  When a contract involves a Subject to sale addendum, when does the Earnest money become non-refundable?  Refer to sections 1A and 1B of the Subject to Sale addendum.

When writing an offer using a Subject to Sale Addendum use hard dates in the REPC in section 24.  Or you may use “X days” after Buyers home is under contract in section 24a, b, c, and d.