Alternate RTH Background Only

This “Alternate RTH Background Only” script highlights the chart background in alternating colors for each new day during the regular trading session (9:30–16:00 EST). It detects the start of a new calendar day (midnight) to increment its day counter, then applies a different semi-transparent color to the 9:30–16:00 bars for easy daily separation. No lines or indicators are plotted—only the background shading changes each day.