Before I moved to the country though, wheat harvest didn't make sense to me. Some called it "amber waves", some called it "ripe", sometimes it was mentioned as "too green", and the Bible called a ready-to-harvest wheat field "white". It might has well been explained in Chinese!
When it comes down to it though, it depends on the type of wheat. A lot of the wheat grown where I live is very green at the start of summer, then it ripens to a golden or "amber" color. Then, right before harvest the field literally turns white. -That's when you harvest. Right then! If you wait, the wheat overripens and is good only for chicken feed.
Amazing huh? God told us to not wait, but to gather the harvest of unbelievers, because the field is white, ready for harvest. If you and I wait... it could be too late for the old lady down the street, the cashier at the SuperPumper, and the little boy who comes to Bible Club. You never know when their time on earth will be done, when death will knock on their door. Will it be your fault they didn't go to heaven?
"Say not ye, There are yet four months, and then cometh harvest? Behold, I say unto you, Lift up your eyes, and look on the fields, for they are white already to harvest." John 4:35