From everything I've read...
24/0 is fine, the advantage is you don't need to have a timer
18/6 is fine, the advantage is your lights are off 25% of the time, saving power and $$$
It was some legit experiment where they tested it, there was either no or negligible benefit from the extra 6 hours of light in 24/0. In the real world, this is one of those times where it truly doesn't matter.
You could change what you have from 24/0 to 18/6 if you wanted to, but don't change repeatedly. I don't have facts about what happens if you do but my gut says it can't be a good thing