kadigaram

According to Ancient Indian clock a day starts at sunrise.
Clock starts 00:00 @ sunrise
Each day has 60 hours (Nazhigai or Gatika)
Each Hour has 60 Mins (ViNazhigain or Palas)
Each Min has 60 Secs (Nodi or Vipalas)

This automatically pulls sunrise/sunset for your location.

Roadmap:
Ability to set recurring alarm before sunrise.
Ability to set alarm at a specific Nazhigai