A cronjob would definitely work in most cases if the goal is just to auto change freq profiles during set ToU periods. I just wanted a more flexible system where the system can auto change the profiles based on actual utilization so demanding tasks aren't slowed down.

I'm on a time of use rate plan, most expensive from 11am-7pm. However they also have "Critical Peak Events" which increase the rate about 10x to over a $1/kwh that last up to 4 hours. Just saying it would be a bit more complex then just checking the time.