Ramadan is the ninth month of the Islamic calendar.

斋月是伊斯兰历的第九个月。

Residents say fighting intensified around Khartoum on the first day of the holiday - one of the most celebrated festivals on the Islamic calendar.

居民们称，喀土穆周围的战斗在伊斯兰历上最著名的节日之一宰牲节的第一天加剧。

This journey, also know as the hijra, is so important that it marks year 0 in the Islamic calendar.

这段旅程，也称为 hijra，非常重要，它标志着伊斯兰历法中的第 0 年。

The exact start date of Ramadan changes because it's based on clerics seeing a crescent or new moon as the Islamic calendar follows the lunar cycle.

斋月的确切开始日期会变化，因为它是基于伊斯兰历的月相或新月而定的，伊斯兰历遵循月亮的周期。