- At some point in 1991:
- Dudley turns eleven. The Dursleys go to the Zoo to celebrate, taking Piers Polkiss and Harry Potter with them. At the zoo, Harry talks to a boa constrictor in the Reptile House and releases it from its confinement with a burst of accidental magic when Dudley shoves him out of the way (PS2).
- Last week of July:
- The first Hogwarts letters arrives in Privet Drive. Though Vernon and Petunia refuse to let Harry Potter get his letter, more arrive. Uncle Vernon tries to keep the letters from coming by boarding up the doors and windows, but the letters still come; finally, he has a mental breakdown and the family leaves the house, traveling aimlessly in an attempt to escape the letters. However, the letters keep arriving. Vernon then decides to buy a gun and rents a shack on an island during a storm, where the family stays for the night.
- July 31:
- Harry turns eleven years old (PS8).
- Hagrid breaks into the hut less than a minute after midnight, bringing Harry a cake. He gives Harry his Hogwarts letter, tells him the true story of his parents' deaths, and gives Dudley a pig tail when Vernon insults Albus Dumbledore. He also sends Dumbledore a letter informing him that he has picked up Harry and given him his letter (PS4).
- Hagrid takes Harry to Diagon Alley to buy his school supplies.
- Hagrid retrieves the Philosopher's Stone from Vault 713.
- Harry meets Draco Malfoy in Madam Malkin's. Draco talks with Harry about Hogwarts Houses and Quidditch to Harry, insults Hagrid, and shows his prejudice against Muggle-borns (PS6).
- Hagrid gives Hedwig to Harry as a birthday present.
- Quirrell tries to steal the Philosopher's Stone from Gringotts, but fails, incurring Voldemort's wrath (PS8, PS17).
- Percy Weasley receives his Hogwarts letter, in which he learns that he has been made Prefect. His parents buy him an owl, Hermes (PS6). He gives Scabbers to his younger brother Ron (PA4).
- Vernon and Petunia ignore Harry.
- September 1
- The Dursleys take Dudley to London to remove his pig tail (PS4), and drop Harry at King's Cross (PS6).
- Molly Weasley tells Harry how to get into Platform Nine and Three-Quarters (PS6).
- Harry and Ginny meet for the first time (PS6).
- Harry become friends with Ron during the Hogwarts Express trip. He also meets Fred, George, Neville, Hermione, Crabbe, Goyle for the first time (PS6).
- Harry, Neville, Hermione and Ron are Sorted into Gryffindor along with Seamus, Dean, Parvati and Lavender (PS7).
- Draco, Crabbe and Goyle are Sorted into Slytherin (PS7).
- Harry meets Snape for the first time, as well as Nearly Headless Nick (PS7).
- Quirrell comes back to the school as Defense Against the Dark Arts teacher (PS8).
- September 6
- September 12
- Gryffindor and Slytherin first-years have their first flying lesson (PS9).
- Neville breaks his wrist after falling from a broomstick (PS9).
- Draco steals Neville's Remembrall after he boy leaves for the Hospital Wing with Madam Hooch. Harry get it back after a spectacular flight.
- McGonagall sees Harry flying and takes him to Oliver Wood apointing him as the new Gryffindor seeker instead of punishing him (PS9).
- Draco challenges Harry into duelling with him ([PS9]]).
- Hermione tries to stop Harry and Ron to go the the duel in the Trophy Room. She follows them outside the portrait hole, and they meet Neville (PS9).
- They find out that Draco fooled them and tipped Argus Filch about someone being in the Trophy Room around midnight (PS9).
- The Trio and Neville meet Fluffy for the first time (PS9).
- Mid-late September
- Dumbledore ask Snape to keep an eye on Quirrell.
- Harry's new Nimbus 2000 arrives.
- Oliver teaches Harry Quidditch rules.
- October 31
- A Troll invades the castle, interrupting the Halloween feast. Harry and Ron try to find and warn Hermione about it instead of going to the Gryffindor Common Room as they should. They meet the troll in the bathroom were the girl is hidden and defeat the troll by hitting him with his own weapon by making it fly with a spell they had learn ealier in the same day Wingardium Leviosa (PS10).
- Harry, Ron and Hermione become friends (PS10).
- Quirrell tries to steal the Philosoper Stone but Snape stops him (PS11).
- Early November
- Harry goes to his first Quidditch Match, against Slytherin. He plays agains Terence Higgs, but has a lot of trouble on trying to find the Snitch because Quirrell was cursing his broom. Hermione thinks that it was Snape that was jinxing Harry and set his robes on fire (PS11). Harry wins the game by catching the snith with his mouth (PS11, DH7).
- The Trio first finds out that Nicolas Flamel is involved in the thing hidden in the third-floor (PS11).
- Late December
- Harry and the Weasleys stay at Hogwarts to the Christimans Hollidays (PS12).
- December 25
- Harry recieves several christimans presents, as a flute from Hagrid, and a hand-kitten jumper from Molly. He also receives his fathers Invisibility Cloak (PS12).
- Harry leaves his room alone to walk around with the cloak and finds the Mirror of Erised. He sees James and Lily's face for the first time (PS12).
- December 26