Sonoma Calendar date format

Calendar and Reminders in macOS 13 and earlier did NOT respect the Date Format in the Language & Region settings. The reason you saw YYYY-MM-DD in macOS 13 and earlier Calendar and Reminders was because that was the date format Apple had decided to associate with Canada as Region in the Language & Region settings. In macOS 14 Apple has associated the date format MM/DD/YYYY with Canada as Region in the Language & Region settings. I'm not Canadian but have always used Canada as the Region exactly because it was the only one that was associated with the ISO 8601 date format.

I think I have a relatively good workaround now. Go to System Settings > General > Language & Region, and set the following:

Preferred Languages: English (Canada) - Primary

Region: Paraguay

Date format: 2023-08-19

It' important that the Preferred Language is English (Canada) and not just English because this changes the date format to YYYY-MM-DD on many websites, including icloud.com > Calendar.

Another tidbit is that if you have an Apple Numbers document containing cells that have the Data Format: Currency with Currency: Canadian Dollar, and you want to display those cells as $123 and not CA$123, you have to go to Numbers > File > Advanced > Language & Region... and change the Language from System - English to English and the Region from Paraguay to Canada.

I have the same date formatting problems.

Numbers, Calendar, Reminders don't respect the system format.

A third-party app, CoconutBattery, still follows the system format.

This is super annoying. Feedback sent to Apple.

This remains broken in 14.3.1 (23D60).

Two months ago I filed FB13468535, citing this discussion as well as FB13221469 and FB13221502. As expected, complete silence.

Apple, do you read this stuff? Do you look at bugs we file? Do you accept that this is a defect? Do you plan to address it, or at least acknowledge it?

Yes, as I commented a few weeks ago: Sonoma Calendar date format - Apple Community

Nonetheless, Apple failed to make any mention in the 14.4 release notes, and Apple has still failed to make any response to my bug FB13468535, which remains open.

Also noticed this. It appears the issue is limited to the date picker widget — other aspects of date formatting (e.g. printing out dates) work correctly. But it will affect every app that uses the standard date picker widget; e.g. I'm seeing the issue in Fantastical as well.

Specifically:

1. The NSDatePicker widget does not respect the date format preference you select in System Settings. The format it uses is determined only by the language and region you've selected. (This appears to not be a new limitation — I tested on macOS 13 and it also doesn't change depending on the preference in that version, either.) Filed this as FB13221469.
2. The format NSDatePicker uses for Canada has changed to the US-style "M/d/y" format, instead of the "Y-MM-dd" format that was previously used for Canada. However, the default format that Apple uses for dates for Canada is still "Y-MM-dd" everywhere else, so ... they should switch it back for NSDatePicker to be consistent (and, arguably, more correct). Filed this as FB13221502.

I can't personally verify the specifics of Calendar, but if @Westacular knows what he/she's talking about (and it sure seems like it), his/her first bullet point says that the reason Calendar doesn't respect the Date Format setting is because it uses `NSDatePicker`, which presumably has never respected the Date Format setting. Only people inside Apple know why they have implented their API in this way.

I don't have a workaround. I tried a bunch of different regions, but none of them fixed the issue. But I hope Apple accepts the bug report @Westacular mentions in his/her second bullet point for changing the date format `NSDatePicker` uses for Canada region back to the way it was in macOS 13 and earlier.

Yes, I forgot to mention that setting Region: Paraguay is what changes the date format to YYYY-MM-DD in any macOS app that uses the native date picker (i.e. NSDatePicker), for example when you click to select a date in macOS Calendar or Reminders. Using Region: Sri Lanka also works for that purpose.

I first noticed this with CheckBook Pro, where some pages used my System Setting (Canada & yyyy-mm-dd) and other pages used the illogical mm/dd/yyyy format. I only have one computer running Somona, so I hadn't noticed the issue in Calendar until today (all other computers are pre-Sonoma).

I, too, filed feedback to Apple.

Adam wrote " I'm guessing it's getting the latter format from my region (Canada)." The standard date format in Canada is ISO 8601, i.e. yyyy-mm-dd, and that has been the standard that macOS Region Canada has been for recent (last few decades or more?) macOS versions prior to Sonoma.

Sonoma is well mucked up on the date format. Most apps that have a date component is now broken.