The itinerary says it all:
Oct. 27, 1783, 9:30 a.m: Mozart (then twenty-seven years old) and his wife, Constanze, leave Salzburg, where they had been visiting Mozart’s father. Heading back to their home in Vienna, they spend the first night of their journey in Vögelbruck.
Oct. 28: They arrive in Lambach in time for Mozart to play organ during the morning Mass.
Oct. 29: Opera and party in Ebersberg.
Oct. 30, 9:00 a.m: After three busy days on the road, they arrive in Linz, where they stay with Count Johann Joseph Anton Thun-Hohenstein.
Oct. 31: Mozart dashes off a quick note to his father: “….On Tuesday, November 4th, I am giving a concert in the theater here. And, as I didn’t bring a single symphony with me, I’ll have to write a new one at breakneck speed, since it has to be finished by that time. I must close now, because I have to get to work.”
Nov. 4 (four days later): Mozart conducts the premiere of his new symphony with Count Thun’s orchestra.
Symphony No. 36 in C Major, K. 425, "Linz"
By Wolfgang Amadeus Mozart
Composed in 1783