Depends on which type of account you have and whether you pay it in through a cash machine or over the counter. If you have a current a/c with a chequebook then (including the day you pay it in) it's on the 4th working day (Pay in Mon, spend Thurs).
With savings it's generally an extra day. With "I'm nearing bankruptcy" basic current accounts it's also the 5th w/day.
Paying in through a cash machine adds an extra day on.