In general use, the 7 days of the week are:

1. Sunday – Ravivaar (रविवार)
2. Monday – Somvaar (सोमवार)
3. Tuesday – Mangalvaar (मंगलवार)
4. Wednesday – Budhvaar (बुधवार)
5. Thursday – Guruvaar / Brihaspativaar (गुरुवार / बृहस्पतिवार)
6. Friday – Shukravaar (शुक्रवार)
7. Saturday – Shanivaar (शनिवार)

In Jainism:

• Scriptures do not give any special fixed rule that “this day belongs to this Tirthankar.”
• Any day can be used for upvaas (fasting), pratikraman, paath, samayik, and pooja.
• In many Jain families, by local tradition, people remember certain Tirthankars on specific days, but this is devotional practice, not a compulsory shastriya rule.

If you want, I can also share the commonly followed (non-scriptural) list of which day some people associate with which Tirthankar.