The Greeks named the days for the five known planets and the sun and moon. These were named after Greek gods. The Romans substituted their own gods for the Roman gods. Germanic peoples also substituted the Roman gods for their own with the exception of Saturn.
Sunday was named after the sun. Sunday is thus the day of the sun.
Monday was named after the moon. It is thus the day of the moon.
Tuesday was named after Tiu, the Germanic god of war and sky.
Wednesday was named after the Anglo-Saxon god Woden. He was the leader of the wild hunt.
Thursday was named after Thor, the Norse god of thunder.
Friday was named after Freya, the Teutonic goddess of love, beauty and procreation.
Saturday was named after Saturn, the Roman god of agriculture.
The English days of the week correspond to the sun, moon and five planets. These planets were named after gods. Saturday was named after a Roman god, but the others were named for gods of the Germanic peoples. In the past only five planets were known