3 month old crying in evening inconsolably

My 3mo+ baby started crying inconsolably since last few days in evening. I try to feed, take a walk, take him out but nothing seems to work. He cries until he gets tired enough to fall asleep. He takes about 2 naps during the day and this starts around 6:30pm. I don’t think it’s colic because his tummy is fine otherwise, no changes to my diet and he is completely breastfed. Any advice is appreciated. Thank you