Getting Back to Exercise

I never imagined how hard it would be to find time to workout once I went back to work.  I have always been in decent shape and having a kid is no excuse to change that now. 
I started trying, trying being the key word, to get back into an exercise routine after my 6 week follow-up appointment at the doctor.  Carter's napping patterns were all over the board which made finding 30 free minutes hard.  There were days I got a little exercise and other days I got none.  Then Scott and I decided to do the 30 day squat challenge which seems to be all the rage right now.  I wasn't thinking wisely when we started b/c the last 10 days of the challenge were right when I started back to work.  Luckily we never missed a day and today is the last day!  
Now I am trying to figure out what is next.  I need to start working on my abs and the rest of my body and try to mix up my workouts a little. 
It's the "When" that I can't seem to decide on.  I know it's not going to happen in the morning.  I really don't want to get up earlier than 5:30am.  I don't really want to workout while Carter is awake after we get home from work because I would rather spend time with him.  So that leaves after he goes to bed around 8:15-8:30.  By this time of night usually all I want to do it sit down for a bit before I take a shower, but I guess that is what the weekends are for. 
Working out at night kind of eliminates much running outside, but hopefully I can get back into the CrossFit style workouts and get myself back on track. 

So here's to hoping that I can dig deep and suck it up and start working out at night.  I guess the upside is that it will be cooling off outside by that time of night.