Let’s have a little look at the names of the days of the week, as appear nowadays, in the English language as well as their (substantially Norse/Scandinavian) origins and meaning now:

Monday, to begin the week with, means ‘Day of the Moon’ and likely derives via the Middle English Monenday on the Old English Mōnandæg, which in turn most likely comes from the Old Frisian Mōna(n)deig.

That said, the Middle English version looks very much identical to the Old Frisian alternate form of Mōnendei, so it may well have been obtained directly from the latter instead.

Tuesday is ‘Tīw’s Day’ or ‘Týr’s Day’ where Týr (Tiwar in Proto-Norse) is a Norse god of war. The English name of the day comes likely via the Old Frisian Tiesdei, which is almost identical.

Wednesday, in turn, means ‘Day of Woden’ where Woden is no other than the mighty Norse king of the gods Odin. The English name apparently comes via the effectively identical Old Frisian Wednesdei.

Thursday is ‘Thor’s Day’ where Thor is no other than the well-known Norse god of Thunder. Its deep root lies in the Norse Þórsdagr (Thor’s Day, where ‘Þ’ is pronounced as ‘θ’) apparently as an influence on Old Frisian Thuner (Thor) and Thunersdei, with a loss of the ‘n’ through time.

Friday means ‘Day of Frig’ and Frig is no other than Odin’s consort goddess Frigg. The English name comes apparently either through the Old Saxon (Low German) name for the goddess of Fri or Old Frisian Frīadei or Fredei for the day.

Saturday has got its origins in the Roman Latin Sāturni diēs that means ‘Saturn’s Day’ but most likely came via the Old Frisian Sāterdei, with which the Middle English form (Saterday) is effectively identical.

Finally, Sunday means ‘Sun’s Day’ as can easily be made out. Its older form (Middle English) is Sunedai likely to have come in its turn from the Old Frisian Sunnandei.