Difference in ROI from day play and after 6PM play?

[Vetstadium]

I was wondering if anyone had drastic differences in ROI at these different times. I just started using the 2005 spreadsheet and already noticed a difference. It just stinks I am stuck playing at day more often.

[breezeyo]

My stats, including 2004, tell me that my best ROI has been between 7pm and 9pm CST. That is also when the most players are on Party.