A superstitious gardener works from 8pm till 5pm. He insists on having a rest every time the digits on his watch add up to 13.
He starts work again a minute later.
His watch shows hours and minutes in a 24 hour format (no seconds).
What is his longest period of non-stop work?
Answer58 minutes (accept 57 mins and 59 secs) From 9:41 till the clock hits 10:38