31. In fact this is the only Ayyavazhi festival which is celebrated according to the Solar calendar . 32. This indicates that the ancient Somali solar calendar was very similar to the one they use today. 33. It was 23 October 1783 ( Lunisolar calendar ) as 17 November 1783 ( Solar calendar ). 34. Indian calendars like the Hindu calendar, Tamil calendar, Bengali calendar and Malayalam calendar are sidereal solar calendars . 35. Ramadan is based on the lunar calendar, which is 11 days shorter than the conventional solar calendar . 36. The Gregorian calendar is a solar calendar . 37. The object would have permitted the determination of dates or periods in both lunar and solar calendars . 38. In the solar calendar Easter is called a moveable feast since its date varies within a 35-day range. 39. The Thai solar calendar , when based on the zodiacal signs rather than the tropical movement of the earth. 40. Jews gave up the practice of moonsighting 1, 600 years ago, opting instead for a complex lunar-solar calendar .