More than Sunday or Monday
A week-start calendar is a dated grid whose first column is the weekday you choose. Sunday-first is common on U.S. kitchen walls. Monday-first is common in offices and matches ISO weeks. Other starts are not decorations. A Friday-to-Thursday work cycle, a Saturday-first household, or a Wednesday payday week all need the first column to match how people actually plan.
The generator rotates the seven weekday headers. January 1 does not jump into column one unless that date falls on the weekday you picked. The dates stay honest. Only the column order changes.
Weekly layouts follow the same setting. An hourly week that starts on Tuesday begins that Tuesday. A meal planner that starts on Sunday keeps the weekend on the left. A workweek layout still drops Saturday and Sunday from the hour grid, even if the week-start control is Friday; those two days stay off that sheet because the job is a five-day timetable.
ISO week numbers, when you turn them on, still count Monday-based ISO weeks. The gutter is a reference, not a second start setting. If that mix looks odd, use Monday start when ISO numbers are visible.
Print a sample month twice if two people in the house disagree. Paper is cheaper than a year of reading the fridge in different directions.