First let's solve the clues, noticing the pattern in each answer as we go:
Namely, that the three shaded squares contain an abbreviated day of the week (Sun, Mon, Tue, etc.), in turn:
1 end of the day = [sun]seT
4 us state = [mon]tAna
6 1971 french open quarter-finalist for women's singles = [tuE]ro
2 tie the knot = [Wed]
7 loud noise = [thu]D
5 search for items = [fri]sK
3 quenched = [sat]Ed
In other words, as suggested by the title, these cells' values are pre-determined to be days of the week.
Now look at the numbers beside each clue...
Since these are numbered 1 to 7, these suggest we should extract the circled letters from each word and reorder them according to this numbering. Doing so produces the word TWEAKED.
All of which fits thematically, since we conclude that 'this puzzle must be tweaked' - in that we had to reorder ('tweak' the arrangement of) the letters to form this final password, and this word contains a homophone of 'week' within its pronunciation.
(At least that's what I thought the relevance of 'tweaked' was, until this wonderful follow-on puzzle was posted immediately after this one was solved...!)