Varshi Tap (Varshitap) is a one‑year long vow of alternate‑day fasting, done in remembrance of Bhagwan Rishabhdev.

In traditional practice:

• Parna (completion) is done on Akshay Tritiya (the day Bhagwan Rishabhdev did parna with sugarcane juice).
• So, the start of Varshi Tap is normally on Akshay Tritiya of the previous year, and it continues (ekaas / beas style) until the next Akshay Tritiya, when parna is done.

So in simple terms:

> You usually start Varshi Tap on Akshay Tritiya and complete it on Akshay Tritiya of the next year.

However, in many sanghs, exact dates are fixed by the local guru / pandit according to the Jain calendar (tithi, sunrise timings, etc.). For the precise calendar dates for a particular year and your city, you should follow:

• The Jain panchang used by your sangh
• Or the guidance of your guru / pravachankar / sanghpati

If you tell me your city and which year you are asking about, I can explain how to find the exact English calendar dates step by step.