I can't mark timespan with DHXTimeSpan.Type.BlockEvents.

I need to mark color in block of each event day.
my coding in below, doesn’t work.
Schedule.TimeSpans.Add(new DHXMarkTime()
{
CssClass = “red_section”,
SpanType = DHXTimeSpan.Type.BlockEvents
});

but Mark timespan of Saturday have work done.

Schedule.TimeSpans.Add(new DHXMarkTime()
{ Day = DayOfWeek.Saturday, CssClass = “green_section” });

my css
.red_section {
background-color: #ff0000;
}