Let’s say that she lies on Monday and Tuesday is itself a lie. That would mean one of those two days she tells the truth.

Let’s say “today is either Thursday, Saturday, or Sunday” is a lie. That would mean today is either Monday, Tuesday, Wednesday or Friday

Let’s say that she lies on Wednesday and Friday is itself a lie. That would mean one of those days she tells the truth.

Sunday?
Hint 1 (Sunday): can be true because it is not Monday or Tuesday
Hint 2 (Monday): can be a lie because it is not Thursday, Saturday, or Sunday
Hint 3 (Tuesday): is true, Wednesday and Friday are both lying days, so can’t be this day

Monday?
Hint 1 (Monday): hint 1 says Monday is a lie day, but this would be a truth day.

Tuesday?
Hint 1 (Tuesday): lies on Monday and Tuesday, so can’t be Tuesday.

Wednesday?
Hint 1 (Wednesday): lies on Monday and Tuesday, that’s true.
Hint 2 (Thursday): today is Thursday, Saturday or Sunday. This is true, so it can’t be Wednesday.

Thursday?
Hint 1 (Thursday): lies on Monday and Tuesday, that’s true.
Hint 2 (Friday): today is Thursday, Saturday or Sunday (yep that’s a lie)
Hint 3 (Saturday): lies on Wednesday and Friday (both are lies!)

Therefore it’s Thursday.

Abe doesn’t know which hat he is wearing, so the two in front must be either 1 red 1 blue or 2 blue. Can’t be 2 red or Abe would know his is blue.

Bill doesn’t know which hat he’s wearing, but he knows it must be 1 red 1 blue or 2 blue. If the hat in front is blue, then he would know his is red. Therefore the hat in front must be red.

Cal’s hat is red.