Diary

Greg's diary is the biggest job in the series. Without it, there would be no way to to know what happens in his life. So far there have been 7 of them. The first one is red, second is blue, 3rd is green, 4th is yellow, 5th is purple, and 6th is icy blue, 7 is brown, and 8 may be atomic tangerine. All of them say DIARY on the cover.

Trivia

 * ​Each diary has it own months. So far in all Diarys, there are a total of 30 months
 * Ist owns September, October, November, December, January, February, March, April, May, and June
 * 2nd owns September, October, November, and December
 * 3rd owns January, February, March, April, May, and June
 * 4th owns June, July, and August
 * 5th owns September, October, and November
 * The 6th and 7th book have the least month then the others. 6th owns November and December and 7th  owns January and Febuary
 * In Rodrick Rules, it was later revealed that Rodrick took his First Diary away and fails. Then Greg lost his Diary after going in the Lady's bathroom and then the police took him away. And then Rodrick saw the whole thing on Grandpa's TV and he blew his secret away 4 months later.