apple use it in the messages app for today messages Today 11:45 AM Yesterday 11:45 AM
i see it in the apple developer site
To specify a custom fixed format for a date formatter, you use setDateFormat:. The format string uses the format patterns from the Unicode Technical Standard #35. The version of the standard varies with release of the operating system:
Calendar Fields
fields ( alias | (field*, special*)) > field ( alias | (displayName?, relative*, special*)) >
Translations may be supplied for names of calendar fields (elements of a calendar, such as Day, Month, Year, Hour, and so on), and for relative values for those fields (for example, the day with relative value -1 is "Yesterday"). Where there is not a convenient, customary word or phrase in a particular language for a relative value, it should be omitted.
how to use it in Xcode?
use
– setDoesRelativeDateFormatting:
this logs
Today, 11:30 AM
on en_US locales.