How to use 's and ' without "s" correctly?

[Schwartz]

According to the topic, I know 's is referred to possession, but I'm not sure how to use 's and ' without "s" correctly.

[Anonymousdt]

If nouns end with s, we use ', another case, we use 's. For example:
Tom's book, a week's holiday...etc
Ten minutes' break, two hours' delay...(not use Ten minutes's break, two hours's delay)

[Schwartz]

???? Do we actually need ' on those example you gave.
Ten minutes break, two hours delay both seem correct by themselves.

[Milanya]