Taken from Google
Today marks the start of Ramadan for our Muslim Brothers and Sisters as it
Note that in the Muslim calander, a holiday begins on the sunset of the previous day, so observing Muslims will celebrate Ramadan on the sunset of Sunday, the 31st of July.
Although Ramadan is always on the same day of the Islamic calendar, the date on the Gregorian calendar varies from year to year, since the Gregorian calendar is a solar calendar and the Islamic calendar is a lunar calendar. This difference means Ramadan moves in the Gregorian calendar approximately 11 days every year. The date of Ramadan may also vary from country to country depending on whether the moon has been sighted or not.