Persian days of the week
The Persian week has a tidy logic once you notice that most days are built on counting.
The week starts on shanbe شنبه (Saturday). After that, most days are literally numbered from it.
Counting through the week
Yekshanbe یکشنبه (Sunday) is "one-shanbe," doshanbe دوشنبه (Monday) is "two-shanbe," seshanbe (Tuesday), chaharshanbe (Wednesday), and panjshanbe پنجشنبه (Thursday) follow the same pattern.
Friday stands apart
Jom'e جمعه (Friday) breaks the pattern with its own name. It is the main day of rest in Iran, the equivalent of a Sunday in many Western countries.
The Iranian weekend
Because the week starts on Saturday, the weekend in Iran traditionally falls on Thursday afternoon and Friday, not Saturday and Sunday. This catches a lot of travellers and remote workers off guard.
Notice the counting pattern from shanbe, remember that jom'e is the day off, and the Persian week stops feeling foreign.