Please add a way to select Time Zone from Format Instrument's Data Range section

Today's Date : 2012/09/21
PC's timezone setting : GMT+9(Seoul, Korea)
IB's NKZ12 symbol is from SGX and SGX's timezone : GMT+8(Singapre)
NKZ12's Session modified from QM : 00:00-23:59
I want to plot IB's NKZ12 symbol (1 min chart) with 1 Day Back or From(2012/09/21)-To(2012/09/21) based on SGX timezone, not local timezone.
Format Symbol's Time Zone for Display : Exchange
Format Symbol's Data Range : 1 Day Back or From(2012/09/21)-To(2012/09/21)
 
The NKZ12 chart's first bar timestamp is 2012/09/20 23:00:01, not 2012/09/21 00:01:00.
The display timezone is Exchange, but the loaded data range is local.
I want both to be Exchange based. 
This is because the Format Instrument's Data Range always refers to local timezone.
We need to set the Data Range based on Exchange and GMT too.
 
So, please add a combo box for selecting timezone from Data Range as we have one from Display.