Sepp Hedel from Germany logged 333 in-game years on FM Touch 2017 that makes his record for the longest single save of Football Manager equates to 1,940 hours of real-world play time.
Sepp started his career in December 2017 when working in Africa. While away from his family and friends he set his sights on breaking a record on his favourite game.
One of the rules of the record is that the player is not permitted to pad out their game time by taking holiday. The allowance is no more than 5% of game time can be taken as vacation, however Sepp decided he wasn't going to take any.
Over the course of Sepp's staggeringly long in-game career on Football Manager 2017, he managed three different clubs; FC United, Bengaluru FC and Hereford FC playing 15,768 games and winning 11,217 (71% win ratio).
Sepp started his game in the National League North and only reached the Premier League in 2023, so the well-known star players of today had mostly retired. But he did get the chance to striker Fernando Robles into a goal machine, netting 427 times in 587 games.
Previously the longest single game of Football Manager was 221 seasons achieved in December 2017 by Michał Leniec (Poland), which beat the 170 in-game years achieved by Seb Keenan (UK) three months previously.
You can find more details on the official article on Guinness World Records.