From the documentation, I understand that the BarZone variable is an integer, and it can accommodate most of the world market time zones. I'm using Zorro for Indian markets and IST happens to be GMT + 5:30. I request the developers to implement accommodating time zones in 30 minutes (or 15 minutes to cover all the time zones) increments and introduce IST as a constant (like WET, EST etc.) in future Zorro versions.