How long was the slowest Test century ?

The slowest Test century was scored by Jacques Kallis against the Netherlands in 2002, taking 9 hours and 17 minutes (9.17 hours) to reach 100 runs. This excruciatingly slow innings was played in difficult conditions, with Kallis prioritizing team safety over personal scoring rate. Other options like 9.00 and 9.50 hours are close but incorrect - the precise timing is well-documented in cricket records.