Can't have sex on peak day

Courtney
I have a question! My husband is a firefighter and is on 24 hour shifts every 3 days. I took an ovulation test yesterday and it said "low" then this morning it said "peak" around 11 am. He is working today :( we did it last night before bed (around 11 pm). Would it be just as effective if we did it last night and tomorrow when he gets off?