different session setting, indicator doesn't plot...

["Shraga(Feivi-Philip)" <shraga@xxxxxxxxxxxx>]

For some complicated reason, I have to plot an indicator on an SP chart 
BEFORE the chart starts. I increased the session hours in GS , and the 
chart indeed expands to show the empty non-trading hours before the market 
starts trading. However, if I try to plot an indicator in those "empty" 
hours, even something as simple as "if time<"when symbol starts trading" 
then plot1 (value);", nothing plots...

Can anyone explain the reason for this to me?

TIA

Philip