Origin of each days of the week

 The days of the week originated from ancient Roman and Germanic cultures, and were named after celestial bodies and ancient gods.

Here's the origin of each day's name:

1. *Sunday*: Named after the Sun (Latin: Dies Solis)

2. *Monday*: Named after the Moon (Latin: Dies Lunae)

3. *Tuesday*: Named after Tiw (Norse god of war and law), equivalent to Mars (Latin: Dies Martis)

4. *Wednesday*: Named after Woden (Norse god), equivalent to Mercury (Latin: Dies Mercurii)

5. *Thursday*: Named after Thor (Norse god of thunder), equivalent to Jupiter (Latin: Dies Iovis)

6. *Friday*: Named after Frigga (Norse goddess), equivalent to Venus (Latin: Dies Veneris)

7. *Saturday*: Named after Saturn (Latin: Dies Saturni)

The Roman names for the days of the week were adopted from the ancient Greeks, who in turn named them after the planets in their solar system.