Sperms can survive in the female reproductive tract for nearly 5 days, so I would recommend target the 2 days prior to your ovulation day. As tracking ovulation is not exact science, you may miss the window if you just try on the day of ovulation.
I would do both
In addition to the above advice, sex every day can lower sperm count. So just make it count.
Your not guaranteed you've got the ovulation date exact...so think I would actually have sex the day before ovulation and the day after.
When we were going through fertility help etc they said not to have sex everyday. Sperm quality gets worse. Every 2-3 is what is recommended as they live long enough to cover you anyway. Also an app may say when you are due to ovulate and be wrong. I was a week later than standard ovulation when I got pregnant with my daughter.
@Natalie she's tracking LH, which is different than the monthly guessing apps do. LH only peaks the day before ovulation no matter what the calendar says. It's a lot more accurate. You'll be ovulating within 12-24 hrs after a high LH for the vast majority of people. My ovulation wasn't standard either, so it was super helpful for me to track it so I could get a better idea.
So I have been on clomid trying to conceive and it messed up my window predictability. My lh started peaking day 14 but I didn't see egg white cm until day 16 (and was consistently ovulation around day 18 previously) so nothing is definite. My husband and I, at the recommendation of my doctor, had sex every OTHER day beginning at day 12 (2 days before potential ovulation) until the egg white cm disappeared. Consider doing basal body temp as an additional data point to see what that shows you if you aren't sure. But to answer your question about when, if you know the date I would say 2 days before and day of OR day before and day after.
@Anna thank you so much. This is really helpful!
Both, just have sex both days