in which country is vikram sambat the official calendar
Vikram Samvat Vikram Samvat (Hindi: विक्रम सम्वत्) (abbreviated as V.S. (or VS) or B.S. (or BS));  Listen (help·info)) is the historical and official Hindu calendar of Nepal. It uses lunar months and solar sidereal year (see: Vedic time keeping).
Euphrates The Euphrates (/
Gregorian calendar The Gregorian calendar is internationally the most widely used civil calendar.[1][2][Note 1] It is named after Pope Gregory XIII, who introduced it in October 1582.
Lythrum salicaria Native to Europe, Asia, northwest Africa, and southeastern Australia.[2][6][7][8]