Legal Question in Real Estate Law in California

I assume you were the former owners, and not tenants. The answer would be different. Technically, you lose the right to remain in possession as soon as the buyer records the trustee's deed, but the buyer also has no legal right to do a self-help eviction process, and must give you a three-day notice, then file and serve and win an unlawful detainer lawsuit. Assuming you have no ground to defend the UD lawsuit, the matter will proceed as a default case and the buyer will get a writ of possession within, roughly, a couple of weeks of recording the deed, and the sheriff will be around to remove you a few days after that.

There is a number of variables in how long it takes. These include how promptly the new buyer wants you out, how quickly you are served with the notice and then the suit, how crowded the court's schedule is, whether you appear and oppose the UD suit, how quickly the owner/plaintiff turns the writ of possession over to the sheriff for action, and how busy the sheriff is. I'd say three weeks total would be on the fast side, but if it takes five weeks, someone is dragging things out, intentionally or not.