Feeding time..

A new parent here whose baby is one month 9 days old. May I know for feeding time at night, was told by the hospital that I have to wake baby up every 3hrs for feeding, so if baby’s sleeping pattern is getting longer eg sleep for 4-6hrs at one go instead of waking up crying for milk every 3hr interval, should I still wake him up to feed? If yes, when should I stop waking him up for feeding? Thanks..