Plot low of first bar of regular session

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The simplest solution to this is to make sure you do NOT included extended hours data on the chart. This code will not work correctly if you include extended hours on the chart. If you need a solution that works when extended hours is included on the chart I will not be able to provide that free of charge in the Q&A Forum.

def newDay = GetDay() <> GetDay()[1];
rec firstBarLow = if newDay then low else firstBarLow[1];
plot targetLow = firstBarLow;