One day’s worth of errors on Yahoo! is more than I can handle. Here’s just one goof that you’ll find on Yahoo! omg!:
If you want to impress your friends by writing excruciatingly correct text, you’ll put an apostrophe in that expression: three days’ notice. The Associated Press style guide calls this a “quasi possessive.” You can figure out if an apostrophe is required by substituting the word “one” for the number in the expression. So, you’d substitute “one” and come up with one day’s notice. Did you see that you didn’t use day, but used days? It just sounds right. But the only way it would make sense is if days is possessive. So, a possessive is required in that phrase. Similarly, you’d write one week’s pay and four years’ experience.