Short Riddles and Answers

Question: I work in a battle of wits. The battle is again with only two while an army each has. Each must take a turn in stratagem but to win the leader must die. What am I?

Question: When the day after tomorrow is yesterday, today will be as far from Wednesday as today was from Wednesday when the day before yesterday was tomorrow. What is tomorrow?

Question: Using 3 periods (.) and 1 question mark (?) make this a logical and grammatically correct sentence:

"That that is is that that is not is not is that it it is"

Question: What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

Question: I am first in earth A second in heaven I appear twice in a week But you can only see me once in a year You can also see me in the middle of the sea What am I?