1.   Because Islam follows the lunar calendar, which is shorter than the solar calendar, the dates of Ramadan change every year.

2.   Because the Jewish holidays follow a lunar calendar, they fall on different dates every year.

3.   Because the lunar calendar does not correspond directly to the Western calendar, Lunar New Year can fall anywhere from late January to late February.

4.   Because the Muslim calendar is tied to the lunar calendar, Ramadan begins on a different day each year.

5.   By the Tibetan lunar calendar, which calculates the months slightly differently, the new year, or Losar, begins Wednesday.

6.   It follows a lunar calendar and thus migrates through the year, falling in different seasons.

7.   It is the ninth month on the Islamic lunar calendar and is a month of fasting.

8.   It is worthwhile to check guidebooks for these lists, especially if they are religious holidays that may shift with a lunar calendar.

9.   Muslim and some Asian holidays are determined by the lunar calendar but may vary from country to country based on local lunar observation.

10.   Muslims believe that Ramadan, the ninth month according to the lunar calendar, was when God revealed the Quran to Muhammad.