OK.... In and on can be used in time. For example: I came to the USA in 1985. American celebrates it's independence on July 4th. Use on for events that happen on an exact date or time. Use in for months, years or longer periods of time. ON and IN can also be used in the placement of things. Example. The paper is on the desk. (It's on top) The paper is in the desk. (inside)
Has and Had show possession. They tell the time. Example: "Thomas had a book called The Giver." This means that Thomas isn't in possession of the book anymore. If we say: "Thomas has a book called The Giver.", then Thomas still has the book.
I hope this helps you.