What a difference that one day made!

[diamondcutter]

What a difference that one day made!

http://files.havefunteaching.com/worksheets/reading/reading-comprehension/are-you-listening-third-grade-reading-comprehension-worksheet.pdf

This is the last sentence of the story on the website above. I’d like to know if the use of “that one day” is correct. If I were the author, I would write like this leaving out the word "one".

What a difference that day made!

What do you say?

 

[jutfrank]

The word one is important in that it emphasises that it was just one day that made a difference.

 

[Skrej]

Without 'one', the focus is about the difference that was made rather than it being made in just one day.

What's key here is that such dramatic improvement is not typically expected in just one day.

 

[probus]

It's also an allusion to the proverb or folk-saying "What a difference a day makes."