Why does almost all astrology software (e.g. Jagannatha Hora vs others) show a difference in the dates/days for the Vimshottari Dasha analysis of a person? Which one do I consider the most accurate?

PVR Narasimha Rao decided against releasing the Android version of Jagannatha Hora, probably because of difficulties in preserving its quality and functionality on mobile devices. Mobile development may present challenges related to screen size, user interface, and optimising performance. Furthermore, he might have chosen to concentrate on the desktop version, where the software could be more stable and equipped with additional features, guaranteeing precise and dependable astrology computations.

It will be incompatible with Macintosh/Apple systems running MacOS, iPads, iPhones, Android devices like phones and tablets, as well as other non-Windows platforms such as Linux, Unix, Solaris, and others. However, individuals are utilizing it on MacOS and Linux through Windows emulators. 

Jagannatha Hora usually is accurate but may show discrepancies based on customizable settings. You must verify all settings to ensure accuracy.

Downloading and istallation of the program Jagannatha Hora is free.

You are looking for astrology or horoscope software that creates a personalised birth chart (also called a natal chart or Kundli). Such software typically:

• Takes inputs like date of birth, exact time of birth, name, and sometimes place of birth.
• Generates detailed reports covering past influences, present circumstances, and future predictions.
• Outputs a downloadable PDF report with interpretations, charts, and predictions.

Astro.com, AstroSage, TimePassages, or ProKerala are a few software that provide detailed horoscope predictions and downloadable PDF reports.