What is the burden of proving excusable neglect?

The burden of proving excusable neglect is upon the defendant who must establish his thesis by a preponderance of the evidence. Bruskey v. Bruskey, 4 Cal.App.2d 472, 479, 41 P.2d 203; Caton v. Caton, 131 Cal.App.2d 451, 458, 280 P.2d 876. To decide whether the burden has been met in this respect is the duty of the trial court and an order granting or denying a motion to vacate a judgment will not be reversed on appeal unless an abuse of discretion is clearly shown.