Confused about 民国 dates on receipts I have been in Taiwan for about two weeks.  Some of my shopping receipts have 民国 dates, some have Gregorian, and some have both. What I find confusing is that when there is both, the day is not always the same on both. And I have at least two receipts with the same 民国 date but the Gregorian dates differ by two or more days.
民国 (Republic of China) era starts from 1912. Therefore, just add 1911 to the 民国 year number and you'll know the Gregorian year number. For example, 民国106年(ROC Year 106)=1911+106=2017 A.D.

Sometimes, 民国 is omitted for simplicity. To distinguish ROC year from Gregorian year, follow this rule:

If a year number is relatively small (no matter whether it's larger than 100), it's an ROC year number. (Therefore, 98年 (Year 98) is not Year 1998, it's Year 2009).

The above rule only applies to daily life, not for academic use. However, the date of the year should remain the same on both ROC date system and Gregorian date system. If you see differences, it must be produced by "magic" reasons rather than different date systems.