I'm sure you meant cheques, paper bills of exchange for money. I've had biggies from reputable sources (other banks, Lottery company etc) clear in four bank working days. Personal account ones sometimes take an extra day, but no bank person I've asked has ever given me a satifactory explanation as to why it should even take four days.
When you pay the cheque in you can ask (for a fee, of course!) to "Express" it. This means that, provided the funds are available in the cheque writer's account, you get the money either next bank working day or the bank working day after. See, it can be done!
N.B. Bankers are robbers in striped pants!