SMC KZ NY

This script plots vertical lines on the chart to highlight KZ opens and closes based on New York time.

Key characteristics:
The indicator is plotted on the price chart (overlay).
It draws thin, dotted vertical lines at specific kz.
Killzones are calculated using the America/New_York timezone to ensure correct alignment.
Only weekdays (Monday to Friday) are considered.
The script draws sessions for today and up to one week back (maximum 7 calendar days).
All drawings are created once on the last bar to avoid duplicates and performance issues.
Each session has its own color for clear visual distinction:

• Asia KZ(open)
  
• London KZ (open and close)
  
• New York / KZ Morning (open and close)
  
• Lunch (open and close)
  
• New York / KZ Afternoon (open and close)
  

The Asia KZ open at 20:00 NY is intentionally excluded on Fridays, as there is no valid Asia KZ start on Friday evening.
The vertical lines extend across the entire visible price range of the chart.
The script is optimized to stay well within TradingView object limits.

Purpose:
The indicator is designed to give traders a clean, non-intrusive visual reference for key KZ transitions, helping to analyze price behavior around killzones opens and closes without cluttering the chart.