Thursday is either the fourth or fifth day of the week, falling between Wednesday and Friday. In countries that adopt the Sunday-first convention, it is considered the fifth day of the week. However, in ISO 8601 it is the fourth day of the week. In Slavic languages and in Chinese, this day's name is "fourth" (Polish czwartek, Russian четверг, pronounced CHET-vierg). Portuguese, too, uses a number for this day: quinta-feira, "fifth day", (see Days of the week for more on the different conventions).
The contemporary name comes from the Old English Þunresdæg (with loss of -n-, first in northern dialects, from influence of Old Norse Þorsdagr), meaning "Day of Thunor", this being a rough Germanic equivalent to the Latin Iovis Dies, "Jupiter's Day". Most Germanic and Romance-speaking countries use their languages' equivalents: German Donnerstag, torsdag in Scandinavia, Italian giovedì, Spanish jueves, French jeudi, and Romanian joi. The Hindi word for Thursday is Guruvar, with Guru being the Sanskrit name for the planet Jupiter.