The calendar is a lunar calendar, and months begin when the first crescent of a new moon is sighted. Since the Islamic lunar calendar year is 10 to 11 days shorter than the solar year and contains no intercalation, Ramadan migrates throughout the seasons. The Islamic day starts after sunset. The estimated start and end dates for Ramadan, based on the Umm al-Qura calendar of Saudi Arabia, are:

Can we conclude that is ramadan at the same time every year?
no