Late bedtime

Help mamas! My 4 month old (13 wks adjusted) can’t seem to go down for the night before 9:30pm, some nights we’re trying until 11pm. He has good day naps until about 5pm and then won’t sleep at all until bedtime. Once he’s down for the night he often sleeps till 3-5am and then sleeps again till 7-8 so that’s pretty good. But I would love it if he went down for the night at like 7:30-8pm to give me and hubby some down time alone. By the time baby’s in bed I’m ready to just sleep so it doesn’t give us much time for ourselves. Any tips on shifting that bedtime?