Start Time - Not Period

Hello,

NT8 coding help.

I would like to use the Chaikin Money Flow indicator based on start time rather than period. Meaning- I would like the calculations to run from session open until end of day... not just the last 21 bars.

Current code:
else if (State == State.DataLoaded)
{
moneyFlow = new Series<double>(this);
sumMoneyFlow = SUM(moneyFlow, Period);
sumVolume = SUM(Volume, Period);
}

Any ideas how to get from Period to start time??

Thank you in advance.