Problems Shoot dates

Since having completed my frameforge i have been having real problems managing to get a shoot date that both my main actors can make, I was thinking if there was anyway of filming it so that i could have one of them shoot some days and the other shoot parts another day but as they are both in every scene this was not really feasable. I got this problem because i left finding actors until after i had finished my script, so far doing this project i have learnt that you should start looking for actors as soon as you have your treatment done so that you can make sure you can get the actors for the days you want.