Sunday (day of the sun)
Monday (day of the moon)
Tuesday (day of Tiw)
Wednesday (day of Woden)
Thursday (day of Thor)
Friday (day of Freya)
Saturday (day of the saturn)
Note: Tiw, Woden, Thor and Freya are the names of Anglo-Saxon or Nordic gods
Originally, it was Moon Day, Mars Day, Mercury Day, Jupiter Day, Venus Day, Saturn Day and Sun Day.
Spanish calendar, for instance, retains the moon day, mars day, mercury day, jupiter day and venus day, but changed saturn day to “day of Sabbath” and sun day to “day of the Lord”.
SANDIWARA 
I will add the origins of the name, of the days of the week in spanish
Spanish derives from latin, and many are related to the religion of romans and greeks
………..
LUNES, Monday, day of the moon (in spanish, moon is LUNA)
MARTES tuesday, day of Mars, the god of war
MIERCOLES..wednesday.day of Mercury or the god Mercurius
JUEVES in honor of the godess JUNO, it is also related to the month Junio, June
VIERNES,friday, in honor of VENUS, or Afrodita,
SABADO ,saturday, in honor of SATURN, and also from the Sabbath ,the free day of the jews
DOMINGO, sunday, derives from DOMINICUS, day of the Lord (of God),and is the days for christian catholics to go to church and to have holiday