الفرق بين a three-day holiday و three days' holiday بطريقة جميلة

[Essam ABDOU]

Dear Mr.H0ris0n,
All the rules of using the apostrophe are all BASIC. There are NO EXCEPTIONS concerning periods of time. The only controversial thing about the apostrophe is whether to say: James's school or James` school, and both are correct (on condition that they are pronounced the same way), though the second case (James` school) is more common.
Best Regards!