Advice …. Which day best to ensure we BD

We are keen for baby 3. Logistically BD every day in the fertile window is tricky. Not impossible but tricky. Both have jobs, already have 2 small children and a terminally I'll parent needing 24hr care at home can be exhausting.

If we were to pick one day to defiantly BD to ensure maximum chance, would you suggest peak or day of ov?