Open Settings > General > Language & Region to change your iPhone’s date format, temperature unit, and measurement system. These controls are separate from the setting that changes the actual date, time, or time zone.
Regional settings affect how supported iPhone features display information. An individual app may have its own preferences, so check that app if its display does not change. If you travel, you can adjust these formats without changing the Apple Account you use.
Before changing the entire Region, look for the specific control you need on this screen. For example, Date Format changes the display format without changing today’s date; Temperature changes the unit without changing the forecast itself. This helps you avoid changing other regional defaults unnecessarily.
Change the date format
- Open Settings and tap General.
- Tap Language & Region. This screen groups regional display choices.
- Tap Date Format, then choose the format you want. Return to a date display in an Apple app to see whether it reflects your choice.
Switch temperature or distance units
On Settings > General > Language & Region, tap Temperature to select Celsius or Fahrenheit. Tap Measurement System to choose Metric, US, or UK. These choices are useful when you want, for example, Celsius but do not want to change the phone’s entire region. Apple lists the first day of the week, calendar format, and number format on the same screen.
If you meant to change the current date or clock instead, use Settings > General > Date & Time. Our guide to changing date and time on iPhone covers that separate task.
If a date still looks different in one app, check whether that app uses its own language or region setting, then close and reopen it. Do not change the phone’s region solely to fix one app without checking the effects on its other regional formats.
The Calendar Format and First Day of Week controls serve different purposes from Date Format. Choose the calendar format when the calendar system itself is the issue, and the first-day control when you only want a weekly view to begin on a different day. An app may still present its own layout or formatting options.
Common questions
Will Date Format change the clock to 24-hour time? No. That control is under Settings > General > Date & Time > 24-Hour Time. It changes how time is shown, while Date Format changes the displayed date order or style. A paired watch has a separate switch, covered in how to turn on 24-hour time on Apple Watch.
Why did one app keep its old format? The app may apply its own display settings or may not immediately refresh after a system format change. Check the app’s preferences and reopen it before changing the iPhone’s entire region.
Check which setting controls the display you see
Date order and measurement units can come from Language & Region, while individual apps may offer their own overrides. Change one choice, then inspect a date or measurement in the app that prompted the question. A website can format dates according to its account preferences rather than the phone's region. Likewise, a weather app may offer Celsius or Fahrenheit independently. If the iPhone setting changes but one app does not, look for the app's own display setting before changing the whole device region.
Changing the region can affect more than dates, including default formats and available services. If you only need temperature or distance units, change that specific unit rather than changing the region unnecessarily. Return to the same screen to reverse the change if a different format proves confusing.
Can I change the Weather app’s city list here? No. Cities are managed in the Weather app itself; see how to remove a city from the Weather app.
Will this alter dates already stored in Calendar? A display-format change changes how dates are shown, not the underlying event date and time.
Apple documents these controls in Change the language and region on iPhone.
Matthew Burleigh has been writing tech tutorials since 2008. His writing has appeared on dozens of different websites and been read hundreds of millions of times.
After receiving his Bachelor’s and Master’s degrees in Computer Science he spent several years working in IT management for small businesses. However, he now works full time writing content online and creating websites.
His main writing topics include iPhones, Microsoft Office, Google Apps, Android, and Photoshop, but he has also written about many other tech topics as well.