Fix UTC Bug in Open-Source Astrology Program

I need a programmer to fix a UTC (time zone) bug in an open-source astrology program that casts birth charts. The issue occurs when entering birth data for individuals born in India, where the program incorrectly lists UTC as xx:21. UTC should only ever be listed as xx:00, xx:30, or xx:15 (for Nepal). The task involves identifying and correcting this bug. Familiarity with astrology jargon is preferred but not required. I can provide specific birth data for testing and verification purposes. Other locations like Germany, USA, and UK have been verified as accurate.