How to change the first day of the week in the iPhone Calendar

2 min read · 5 steps · Updated 4 October 2026

Device

iPhone

Shown on

iOS 26.5 (iPhone 17)

App

Settings

Path

Settings › Apps › Calendar › Start Week On

Real screenshots

5 of 5 steps

Checked

October 2026

Sources

1 official, linked below

Whether a week starts on Sunday or Monday depends on the region the iPhone is set to. If the Calendar shows the wrong first day for you, you can change it for the Calendar alone, without changing the region of the whole phone.

The screenshots show iOS 26.5 on an iPhone 17. On older versions the rows have the same names, with a slightly different look.

Step by step

1. 

   Open Settings and tap Apps

   Apps is near the bottom of the main Settings list.

   Done

2. 

   Tap Calendar

   The apps are in alphabetical order, so Calendar is near the top, under C.

   Done

3. 

   Scroll down and tap Start Week On

   It is the second row from the bottom of the page, below Duration for New Events.

   Done

4. 

   See what is selected now

   The tick is on System Setting, with the current day in brackets. In the picture that is Monday. The note below says the Calendar then uses the setting from Language & Region.

   Done

5. 

   Tap the day you want

   Choose any day from Sunday to Saturday under Calendar App Only. The note at the bottom says the choice applies in Calendar only, and other apps keep the system setting.

   Done

Good to know

To change the first day for every app, tap the blue Language & Region link on the Start Week On page.

Week numbers are on the same Calendar page: how to show week numbers in the Calendar on an iPhone.

In short: Settings, Apps, Calendar, Start Week On, tap a day.