Answer

Posh Dasam can appear on January 2, 2027 and also January 31, 2027 because the Jain/Hindu lunar month Posh does not match the January calendar month exactly.

In 2027, there can be two occurrences of Dashami tithi falling in the Gregorian month of January:

• January 2, 2027 — Dashami connected with one part of the Posh lunar cycle.
• January 31, 2027 — another Dashami tithi occurring near the end of the same Gregorian month, due to the lunar calendar cycle.

Explanation

Jain dates are based on the lunar tithi, not the English/Gregorian date.

A lunar month is about 29.5 days, while January has 31 days. Because of this difference, the same Gregorian month can sometimes contain two Dashami tithis related to nearby lunar cycles.

Also, depending on the calendar system used:

• Some calendars follow the Gujarati/Jain Vikram Samvat month system.
• Some may mark the tithi based on sunrise rule.
• Some may show the tithi according to local time zone or location.
• Some may distinguish between Sud Dasham and Vad Dasham.

So one listing may be showing Posh Sud Dasham, while another may be showing Posh Vad Dasham, or the tithi may be displayed differently depending on the panchang rules.

Spiritual Understanding

In Jain Dharma, observances are done according to the correct tithi at sunrise and the tradition followed by one’s sangh or guru-parampara. Therefore, when there is confusion, the best approach is to follow the local Jain panchang used by your temple or community.

Takeaway

Both dates can appear because Jain dates follow the lunar calendar, not the fixed English calendar. For actual observance of Posh Dasam, follow the local Jain panchang and your sangh’s guidance.