This question is one I get all the time. Look at it this way. One fish oil pill typically has 1 gram of fat. A 6 ounce filet of salmon has about 18. You'd never divide the salmon up throughout the day, you just eat it all at once and assume it's providing benefit!
The only reasons you may want to shift your timing that I can think of:
1. If you're getting burps from the capsules, you may want to take them just before bedtime so your burping and sleeping coincide. I know, a little graphic, but now you'll never forget this post!
2. I've had a few clients note that fish oil can make them feel sleepy. That can be a good thing, but in those cases night time dosing is probably best.
Those considerations aside, the best time to take the fish oil is the time that you are most likely to remember to take it.