Or, no it doesn't matter. Ggies07, you're in TX but Bonnie is in CA so the true answer to your question may depend on your utility company and the supply pattern to your house. In my case (here in FL) I don't get cheaper electricity at night, it costs me the same all 24 hours of the day which means it makes no difference cost-wise what time I charge the cars. My solar system produces enough power during daylight hours to fulfill all our needs (cars included) 24/7; so obviously we have a net metering system whereby we over produce during daylight hours and every day the meter ticks backwards until the sun goes down and then it clicks forwards again. At the end of the year I want to come out as close to a net zero as possible.
Whether you use the TOU (time of use) rate will ultimately depend on what your powerco offers and you may need to do some individual calculations as I did. A good solar installer will sit down with you and work that out looking at your usage patterns etc.
Final BTW, I charge both cars at night at different times simply to keep total load to a minimum; extra cautious on safety, if you like. During the day there's A/C, washing machines, dryers, oven, pool pumps etc. running at various times.