upright=1.35|thumb|The Sasanian Empire ca. 620 __NOTOC__ Year 620 (CXX) was a leap year starting on Tuesday of the Julian calendar. The designation 620 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
upright=1.35|thumb|The Sasanian Empire ca. 620 __NOTOC__ Year 620 (CXX) was a leap year starting on Tuesday of the Julian calendar. The designation 620 for this year has been used since the early medieval period when the Anno Domini calendar era became the prevalent method in Europe for naming years.