Slowest Test century took 9 hours spread over 2 days
The slowest-ever century in Test cricket was completed in 557 minutes by Pakistani opener Mudassar Nazar on December 15, 1977. The batsman remained 52 not out at the end of first day's play and went on to make 122 in nearly 10 hours. Interestingly, England batsman Geoff Boycott scored 63 in almost six hours in the same match.