Legal Question in Real Estate Law in California

In general, the counting of days for such purposes is governed by the Civil Code, with sections 7, 10, and 11 being the most important, and perhaps portions of the Federal Consumer Protection Act may apply. The Civil Code provisions say that Sundays and ten or so major holidays are not days for the transaction of ordinary business, and if (for example) a thing must be done by Sunday, it may be done on the following Monday. However, Saturday is treated as an ordinary business day (unless it is also a major holiday like Christmas). So, if you signed a contract on 12/18 (Wednesday), Thursday would be Day One, Friday would be Day Two, and Saturday December 21st would be the third and final day to rescind.

I agree with Mr. Whipped and add the following clarification: If the Sunday or holiday falls in the middle of the counted days it still counts. It is only if the final day to act falls on the Sunday or holiday that you get until the next day. So for example if you signed on a Thursday you would have until Monday but if you sign on a Friday you still only have until Monday.

I'm not aware of real estate listing agreements having a 3 day cooling off period. You had better check with the language of the listing agreement before you start counting days.