No date announced yet. This announcement comes as the finale for season two aired today. Check out the Crunchyroll article for additional information. Synopsis for the source light novels from AniList:

Kicked out by his family and wandering the streets, an unemployed 34-year-old shut-in thinks he’s hit rock-bottom—just as he’s hit and killed by a speeding truck! Awakening to find himself reborn as an infant in a world of swords and sorcery, but with the memories of his first life intact, Rudeus Greyrat is determined not to repeat his past mistakes. He’s going to make the most of this reincarnation as he sets off on the adventure of a second lifetime!