But no matter which one they're in, you know that by calling at 11 local (no matter if you're using the right time zone) you'll be calling during business hours, no need to check "What are normal business hours in India?"
There's always one check in that situation. Whether it's business hours or timezone difference. And you still need to check business hours even in our current system, so might as well just simplify it (which of course isn't happening any time soon).