Change how dates, times, and more display on Mac
You can change the formats used to display dates, times, numbers, and currencies in Finder windows and apps, such as Mail.
Tip: If you just want to change how time is shown in the menu bar, select the “Time format” checkbox in Language & Region preferences, or select the 24-hour option in the Clock pane of Date & Time preferences. To show the date in the menu bar, also select “Show date” in the Clock pane.
On your Mac, choose Apple menu > System Preferences, then click Language & Region.
Click the Region pop-up menu, then choose a geographic region to use the region’s date, time, number, and currency formats.
To customize the formats, click Advanced, then set options.
In the General pane, set formats for numbers, currency, and measurements.
In the Dates and Times panes, do any of the following:
Type in the Short, Medium, Long, and Full fields.
Rearrange or delete elements.
Drag other elements, such as Era or Second, into the fields.
Click the pop-up menus , then choose another way to display the element type. (For example, you can display the month as a number, with or without the leading zero, or as a word, either abbreviated or spelled out.)
In the Times pane, replace AM and PM with whatever you type in those fields (unless you’re using a 24-hour clock).
When you’re done customizing formats, click OK.
Your formats are visible in Finder windows and in some apps. For example, dates in Mail or Notes show your custom format.
To undo all of your changes for a region, choose the region again from the Region pop-up menu. To undo just your changes to advanced options, click Advanced, click the pane where you want to undo your changes, then click Restore Defaults.