hey i played around with your last mod for 0.16 (offline of course) and went of the factorio Wiki and found that days are 25000 ticks, at 60 ticks per seconds, you get: 24 times 60 times 60 times 60 divided by 25000 making "207.36" for a 24 hour day time length. hence i am trying out a modded version of your mod with 24 hours but i thought it would be nice if you extended the maximum day length to that number in your future updates (on 0.17 of course since it really looks like it is on the edge of being released stable...)
so in short 24h = 207.36 multiplier. and the maximum for time and accumulators should be that at least! (great mod by the way!)