How long does an LH surge last

I got a positive OPK yesterday morning and then I still had a positive this morning as well. Does anyone know when exactly I should be expecting ovulation? I haven’t tested again to see if it’s still peaking or not. I just can’t figure out my window and my husband leaves for a business trip on Saturday and has been sick this week 😒🤦🏼‍♀️ hoping for today and tomorrow but not holding my breath