Harry: You are 7 months older.
Ron: You are 2 months younger then him.
Hermione: You are a year older.
Mattheo: You are 4 months younger
Oliver: You are 3 years younger then him.
Neville: You are 6 days older.
Fred: You are 2.5 years younger then him.
George: You are 1 month younger.
Draco: You are 1 year younger then him.
Cedric: You are 1.5 years younger then him.
Tom: You are 1 year younger.
Luna: You are 1 year older then her.
Ginny: You are 3 years older then her.
Percy: You are 5 months younger.
Viktor: You are 2 years younger.
Adrian: You are 1 year younger.
Snape: You are 1 year younger.
Remus: You are 2 months younger.
Regulus: You are 2 days younger.
Sirius: You are 2 years younger.
James: You are 8 months older.
Peter: You are 1 year older.
Lucius: You are 1 year younger.
Tonks: You are 5 years younger.
Roger: You are 4 months older.
Theo: You are 1 month older.
Newt: You are 2 years younger.