This Pine Script is an indicator designed to mark and highlight specific trading sessions on a TradingView chart. Here's a description of the script's functionality:
1. *Session Selection*: The script allows you to select a session time frame using the `session_input` input. The available options for session time frames are "D" (daily), "W" (weekly), "M" (monthly), "H" (hourly), "15" (15 minutes), "5" (5 minutes), and "1" (1 minute).
2. *Session Times*: You can specify the start and end times for three different trading sessions - CBDR (Central Bank Dealer Range), Asia, and London - using the corresponding input options. These times are specified in Indian Standard Time (IST).
3. *Time Calculation*: The script calculates the start and end times for each session based on the specified hours and minutes. It uses the `timestamp` function to create time objects for these sessions.
4. *Session Highlighting*: The script creates rectangles on the chart to highlight each session:
- CBDR Session: A gray rectangle is drawn during the CBDR session time.
- Asia Session: Another gray rectangle is drawn during the Asia session time.
- London Session: A green rectangle is drawn at the top of the chart during the London session time.
5. *Transparency*: The rectangles have a transparency level of 90%, allowing you to see the price data beneath them while still marking the sessions.
6. *Overlay*: The indicator is set to overlay on the price chart, so it doesn't obstruct the price data.
7. *Customization*: You can customize the session times and appearance by adjusting the input values in the settings panel of the indicator.
Overall, this script provides a visual way to identify and highlight specific trading sessions on your TradingView chart, helping traders understand price action in different market sessions.