Months, Days and English Language

[Whickerman]

Why, in the English Language, are all of the months taken from Roman names of months yet the days are (mostly) from the Norse gods (Tiw/Tyr, Thor, Woden, Frigga)?

[wildwood]

Saturday and Sunday comes from the Romans. Monday is anglo-saxon (late Roman).

[seadogg]

Saturday, after Saturn of course, didnt seem to change much from the Roman designation, but Sunday and Monday could have also been Norse sunnandaeg and monandaeg which the Saxons absorbed from the Norse.