That means exactly what I said:
You know your seconds are 14 so if you're aiming for say 12:30:14 you would want to reset at 12:30:00, if you were aiming for 12:30:30 then you'd reset at 12:30:16.
The extra minute is so you have enough time to start up the game again and then soft reset. You wouldn't be able to set the clock to 12:30:00 and still hit your target time, but if you set it to 12:29:00 then that gives you an extra minute.
You know your seconds are 14 so if you're aiming for say 12:30:14 you would want to reset at 12:30:00, if you were aiming for 12:30:30 then you'd reset at 12:30:16.
The extra minute is so you have enough time to start up the game again and then soft reset. You wouldn't be able to set the clock to 12:30:00 and still hit your target time, but if you set it to 12:29:00 then that gives you an extra minute.