macOS NSDateFormatter: difference between weekdaySymbols and standaloneWeekdaySymbols?

[Thomas Harte]

It seems that Apple expect me to know the difference between a standalone weekday symbol and an ordinary weekday symbol for the purposes of NSDateFormatter without any further exposition, but I'm unable to figure it out.

For my locale (en_GB), the two calls return exactly the same thing. I'm not even able to find out whether the difference is a linguistic thing (maybe some languages use different words for the weekdays based on context?) or just a technical thing.

Can anyone enlighten me and/or point me to the appropriate documentation?

 

[robbieduncan]

Actually Apple link to the answer: UTS#35 Date Format Patterns via the Date Formatting Guide for Cocoa.

 

[Thomas Harte]

Oh, thanks! For anyone that finds this thread in the future, the relevant quote from the Unicode Consortium documentation is:

Month, day, and quarter names may vary along two axes: the width and the context. The context is either format (the default), the form used within a date format string (such as "Saturday, November 12th"), or stand-alone, the form used independently, such as in Calendar headers.​