Ah folic don't worry - I think many people are in the same situation. My DH works shifts too, so actually through total opportunity, we will clock up an amazing 1 shag in 7 days this week. We just aren't in the same room at the same time to allow any more!
Thn it really does put the pressure on to get swinging like a good 'un on the one day left!
I used to leave it until bed time. This was terrible as he is a night owl and I go to bed earlier (get up earlier as well, knackered by then). So I would be waiting upstairs whilst he dicked around did nothing downstairs, which would end up with me shouting down the stairs and getting all rejected when he took ages to come up. By that stage I was in a huff and he was arsey and it all descended in to 'how are we ever going to have a baby if you don't...' whinge whinge.
Just read that back - fuck sake! How unsexy! I'd rather not bother!
So after a chat, my new technique is when kissing him hello when he/I come in from work, I just pretend to get all 'ooo, hang on a minute, seeing you all tired and stressy looking from work has suddenly turned me AWWWN!
' and get a bit steamier with the kiss. And off we go!
He seems incapable of turning this down as it seems so 'spontaneous'. Reader, it is not 
Whilst always enjoyable (and I can't say it hasn't put a spring in my step!), it is about 9/10 THE LAST THING I feel like doing at the time. However, it then let's me get on with my evening and go to bed when I want and sleep 
HAve never admitted any of the above to anyone, sssshhhhh don't tell Mr Tante! (Or 'Oncle', as I suppose he technically should be)
Have a nice day!