The current weekday names may actually be an old idol called Yaghut in The Kuran.
Monday is named after the moon. (La Kamar in latinized arabic)
Tuesday is named after Thyr. (TH Sound).
Wednesday is named after Odin. (An idol, Wadd in The Kuran)
Thursday is named after Thunor. (a corrected variant of Thor/Tor for a different place, It was corrected as Thyr in Norway).
Friday is named after Frigh. (An anti-idol)
Saturday is named after Saturn.
Sunday is named after The Sun. (Ash Shams, in latinized arabic).
Knowing this defeats the idol.
Friday also is the day of assembly in The Kuran. (Not Sunday).