Potato clock

[rebbonk]

Paddy goes into a John Lewis department store and asks the shopkeeper, "Excuse me sir, but do you sell potato clocks?"

The shopkeeper looks at him and says, "Are you having a laugh? We sell cuckoo clocks, carriage clocks, grandfather clocks, alarm clocks... what the heck is a potato clock?"

And Paddy says, "I don't know, but I start my new job at nine tomorrow, and the wife said

Spoiler:

'You'd better get a potato clock.'