Primarily from the 14th to the 19th century.
“…Conflict along the fault line between Western and Islamic civilizations has been going on for 1,300 years. After the founding of Islam, the Arab and Moorish surge west and north only ended at Tours in 732. From the eleventh to the thirteenth century the Crusaders attempted with temporary success to bring Christianity and Christian rule to the Holy Land. From the fourteenth to the seventeenth century, the Ottoman Turks reversed the balance, extended their sway over the Middle East and the Balkans, captured Constantinople, and twice laid siege to Vienna. In the nineteenth and early twentieth centuries at Ottoman power declined Britain, France, and Italy established Western control over most of North Africa and the Middle East…. This centuries-old military interaction between the West and Islam is unlikely to decline. It could become more virulent…. On both sides the interaction between Islam and the West is seen as a clash of civilizations. …"
From: http://www.bintjbeil.com/articles/en/d_huntington.html
Samuel Huntington's idea of a "clash of civilization" is not entirely unproblematic. At the most fundamental level one might ask if his portrayal of these two, monolithic, sides is not in reality a false dichotomy. What constitutes "the West" for example? It's a widely used, but rarely defined term. In this case it seems like "the Western world" is only defined as the opposite of the Islamic world, and vice versa. Of course you'll find them to be monolithic, static, polar-opposites if that is the premise of your analysis.