In the gregorian calendar, we split the time in years, months, weeks and days.
A week is the total of seven days.
I was looking at the persan calendar, being one of the most precise known calendar. However, on wikipedia (french page), I cannot find any reference to an "equivalent" of gregorians weeks.
So, is there any other calendar that splits/split months into a unit of measurement we could consider the equivalent of gregorian weeks ?