In Jainism, days of the week are not fixed by scripture for any specific God or Tirthankar. You may worship any Tirthankar on any day.

However, in common Jain household practice, many people loosely follow this devotional pattern for the 7 days of the week:

1. Sunday (Ravivar) – Bhagwan Rishabhdev / Adinath (1st Tirthankar)
2. Monday (Somvar) – Bhagwan Ajitnath (2nd Tirthankar)
3. Tuesday (Mangalvar) – Bhagwan Sambhavnath (3rd Tirthankar)
4. Wednesday (Budhvar) – Bhagwan Abhinandan Swami (4th Tirthankar)
5. Thursday (Guruvar) – Bhagwan Sumatinath (5th Tirthankar)
6. Friday (Shukravar) – Bhagwan Padmaprabhu (6th Tirthankar)
7. Saturday (Shanivar) – Bhagwan Suparshvanath (7th Tirthankar)

Important points:

• This is a popular, devotional tradition, not a rule from Agams or main Jain scriptures.
• Both Digambar and Shwetambar accept that you can worship any Tirthankar on any day.
• Many Jains simply remember all 24 Tirthankars every day (e.g., by reciting the Chauvvisi).

You can read more about this common practice here