Maybe to stop a rush on cash deposits in the case of a banking scare out of hours? ie. rumour / announcement that the bank has run out of money. Seems unlikely.

Maybe to stop a rush on cash deposits in the case of a banking scare out of hours? ie. rumour / announcement that the bank has run out of money. Seems unlikely. More likely is that it's to save money - if there is a cost incurred in supplying money for other banks or keeping the machine filled with cash, perhaps reducing hours is simply a cost saving measure.