In Jain Dharma, tithi means the lunar day. Sometimes people see “different tithi” for the same civil date. This happens because:

• Sunrise rule: Many Jain observances take the tithi that is present at local sunrise (uday tithi). If your city’s sunrise time is different, the tithi counted can shift by a day.
• Different panchang methods: Communities may use different lunar calculations (Surya‑Siddhanta vs. modern drik/observational). This can give a different start/end time for a tithi.
• Month system: Some follow Amanta (month ends on Amavasya) and others Purnimanta (month ends on Purnima). The paksha and “month name” can differ even when the lunar day is the same.
• Day‑part rules: A few rituals use the tithi prevailing at pratah/madhyahn/sandhya rather than only sunrise, creating variation in which civil date is chosen.
• Time zones and geography: Outside India, the same tithi can fall on the previous/next civil date due to time zone differences.
• Sect/tradition practice: Digambar and Shwetambar sometimes schedule festivals by their own traditional rules (for example, Paryushan and Das‑Lakshan), so dates can differ while the underlying lunar principle remains the same.

Essence: The moon decides the tithi, not the civil calendar. Because calculations, rules (which moment of the day), and locations differ, the observed civil date can vary—yet the dharmic intent is identical: to align sadhana with auspicious lunar time.

For simple explanations on tithi and related observances, you can read:

• What is tithi?
• Why do we follow tithi?
• Five special tithis and their importance
• Example of sect-wise festival dating (Paryushan/Das‑Lakshan)