Tough question; it’s multi-layered.
On one hand, a Sim week is A week. They get approximately two days off work/school and attend the other five. One day within one week is clearly just that -a day.
From another angle; a Sim week is an entire season. About three months, maybe a little more.
{My seasons are set to seven days, unless I’m rotating}
Then there are three day pregnancies, frequent promotions {at least low-level}, the seemingly rapid progression of relationships {while still seeming organic/natural to game mechanics} and the finite {and brief} lifespans of the Sims themselves.
With all this last taken into account; I have an opinion that Sims achieve in one week approximately what one might in two years of real life.
That is why I have set a custom age span, somewhere nearly perfectly between normal and long EA defaults; with a greatly extended Adult life stage. I have my own age ranges for each life stage and have set my own aging so that Sims age two years in seven days {aka a week, of course}.