Sterrendei

The ancient name in the Common Tongue for the 'Day of the Stars' that began the week. Its origins lay in the Elves' tradition of a six-day week, but by the time it came to be used in Middle-earth, the week had come to incorporate seven days. After Sterrendei, these archaic day-names followed the sequence Sunnendei, Monendei, Trewesdei, Hevenesdei, Meresdei and Hihdei.

In later conventional use, by the time of the War of the Ring, Sterrendei had become shortened to Sterday. This is coincidentally similar to modern 'Saturday', and can be treated as a convenient translation. However, its function in the week was quite different from our own Saturday, and as the first of the seven week-days, a Hobbit would have seen it as more closely equivalent to modern Monday.