The following is the origin of the pagan names in day order.
Sunday – Dies solis (Latin) which means “day of the sun” from which we get Sunday. Sun worship was marked by the use of the halo, or nimbus, which originated with the pagan Greeks and Romans to represent their sun god, Helios. It was later on that artists then adopted it for use in Christian images.
The halo is actually the sun behind the person’s head, as shown in the painting. It’s easy to recognize once one realizes what it is, although it’s also often stylized to make it less obvious. Originally a very devious way of mixing idolatrous sun worship with Christianity by converts who were not all that converted, and as a result the pagan halo became a very misleading tradition in Christian art.
Monday – Dies lunae (from which comes the word lunar), means moon day, from which we get the shortened version, Monday.
Tuesday – Dies Martis, means mars day, after Mars, the Roman god of war. The day was known to the pagan Germans after their own god of war, Tiw (pronounced too) as Tiw’s (pronounced tooz) day, from which we get Tuesday.
Wednesday – Dies mercuri, means mercury day. Woden (pronounced woe-den) was the Germanic version of the pagan god mercury, and they named the day Woden’s day, from which we get Wednesday.
Thursday – Dies Jovis means Jove’s day, or Jupiter’s day. Thor was the Germanic version of the god Jupiter, so they called the day Thor’s Day, from which we got Thursday.
Friday – Dies Veneris means Venus Day. The Germanic version of this female god was Frigg, or Freyja (pronounced fry-yah), so they called the day Freyja day, from which we got Friday.
Saturday – Dies Saturni means Saturn day, from which came Saturday. The pagans also observed their Saturnalia festival in the last week of December, a time when work ceased, gifts were exchanged, and slaves feasted with their masters.