Every time the vineyard owner goes out, there are more people in the market, even though he hires all he sees at every other visit. Where were these people earlier? See the previous verse for an explanation, but here, that suggestion is called into question. The vineyard owner says they have been standing there all day. This is clearly impossible because he did not hire them earlier. Jesus adds the word "whole" to the word day to make this impossibility even clearer.

As we saw in Matthew 20:3, the Greek word for "idle/doing nothing" is the punchline, the last word in the verse. This criticism of the workers seems more comical than real. The employer knew that these workers were not there all day long because he had been there. He is teasing them in saying that they were. However, his tease is just a prelude to something else. His assumption that these workers were idle all day arises from the fact that they were not working for him, but they were clearly doing other things. This mistake would have been more obvious to people of Jesus's time who would know how a labor marketplace worked, while a landowner might not.

Sometimes, I really don't understand why translators just want to ignore the original Greek. The NIV version here is like someone said, "We can say something similar with different words accenting ideas differently than Jesus did." But why do that? It doesn't even make any religions points, maybe it clarifies the time better for those that don't want to understand how the people of the era saw the time then, but doesn't that help to understand what people heard?