Digging further into the forums and playing around with the properties, I was able to find the event property that fires the beforecellrender event. Also, thismay behelpful to anyone reading this post: using e.start and e.end allowsyou to grab the time the cell is referring to. This is how I was able to compare it with my dates in the db thatwere blocked.

Jay,

Thanks for posting the solution!

An example can be found in Demo/Calendar/CustomBusinessHours.aspx (it's for DayPilotCalendar but DayPilotScheduler works the same way):

    protected void DayPilotCalendar1_BeforeCellRender(object sender, BeforeCellRenderEventArgs e)
    {
        if (e.Start.Hour >= 9 && e.Start.Hour < 12)
            e.BackgroundColor = "#FFF2CC"; // shift #1 
        else if (e.Start.Hour >= 12 && e.Start.Hour < 15)
            e.BackgroundColor = "#FFD9CC"; // shift #2
        else if (e.Start.Hour >= 15 && e.Start.Hour < 18)
            e.BackgroundColor = "#F2FFCC"; // shift #3

        // Turning Saturday and Sunday into business days
        /*
        if ((e.Start.DayOfWeek == DayOfWeek.Saturday || e.Start.DayOfWeek == DayOfWeek.Sunday)
            || (e.Start.Hour >= 9 && e.Start.Hour < 18))
        {
            e.IsBusiness = true;
        }
         */ 

        // or you can change just IsBusiness and you will get the color automatically
        /*
        if (e.Start.Hour >= 10 && e.Start.Hour < 12)
            e.IsBusiness = true;
        else if (e.Start.Hour >= 14 && e.Start.Hour < 16)
            e.IsBusiness = true;
        else
            e.IsBusiness = false;
         */ 

    }