In Varshitap, the basic traditional rule (especially in Śvetāmbara practice) is:

• One day upvās (full fast)
• Next day parnā / bhojan (you eat)
• Repeat this pattern for the whole period (about 13 months 13 days), usually ending on Akshay Tritiya. ( jainknowledge.com)

On the eating day, different maryādā are seen:

• Some do beshna (2 simple meals)
• Many gurus now advise ekāsan (1 simple meal)
• Some, as part of a stricter niyam, keep it almost like coviyār (early, light, before a set time)

So:

• If by “one day upvās and one day coviyar” you mean:

- Fast completely on Day 1 - On Day 2 take only one, simple, timely Jain meal (no night eating, with proper pachchakkhan)

then yes, that is generally within the spirit of Varshitap, and in fact is a stricter way than normal eating days.

• BUT: Exact rules can change by guru, sangh, or gacch. For Varshitap you should:

1. Take pachchakkhan from a Jain monk / nun / or learned guru. 2. Follow their instruction for what is allowed on eating days (beshna vs ekāsan vs coviyār type).

Essence in Jain Dharma: Varshitap is not just “alternate fasting” but pure conduct, careful niyam, and inner tap (pratikraman, swādhyāy, samayik). Food pattern is one part; bhāv (inner state) is main.

You can read a simple explanation of Varshitap here