How to get the date only from a ISO 8601 Date String

What is the preferred way to convert an ISO 8601 Formatted date string to a date string eliminating the Time and the offset information?

I/P : 2020-12-15T15:04:05.567-06:00
Expected O/P: 2020-12-15

The function DATE_TRUNC_STR(inputdate, ‘day’) returns the date with the offset, Is DATE_FORMAT_STR
the recommended way to get the date part only.

Are there any gotchas of using DATE_FORMAT_STR?

You can use one of these

DATE_FORMAT_STR(NOW_STR(), '1111-11-11') 
OR
SUBSTR(NOW_STR(),0,10);