At sundown last night the Muslim observance of Ramadan began. It is the 9th month of the Islamic lunar calendar. While it is fixed on the lunar calendar it varies from year to year on the Gregorian calendar. Muslims are to fast from food, drink, and sex in great efforts to be pious. It is also the month in which Allah revealed the Holy Quran as a guide to the prophet Muhammad.
The above photo is of the Dome of the Rock on the Temple Mount in Jerusalem. The Temple Mount or Haram al-Sharif in Arabic was built in 691 CE and enlarged by Herod the Great. It is built on the site of the second Jewish Temple which was destroyed in 70 CE.
For my Muslim friends in Jerusalem, I'm not sure what the correct greeting is but, may Allah rain peace upon you during Ramadan.