I suspect there's some weird truncation going on here
Hehe, personally I see it the other way around - in a pre-modern world they didn't have a clock, not a digital calendar, not this constantly ticking sense of a tight schedule with booked events and deadlines. When I imagine a pre-modern artisan estimating how long it would take to produce an item, they surely won't even bother trying to calculate if it would be exactly 16 or 13 or 18 days , but just round it to "something like two weeks, plus minus a few days" which then just is expressed in the short-hand format of "two weeks", since in such a pre-modern society everyone knows that estimated times are estimated times and anything beyond two or three days can't be measured precisely, so it just normal to idle around for a few days waiting to see if that "two weeks" meant 16 or 18 days.
What is weird is our contemporary willingness to fit ourselves into such rigid timetables, and then feeling uneasy if things don't happen exactly on the minute they were announced to happen.
But, sure, I also think it might be helpful to display some rough estimate of "will be ready after a week or so". Or, just to add "It was said to take two weeks, and the order was placed 8 days ago", leaving some calculation for the player to do. Let's see how Sami decides to code it =)