[3.11] gh-105031: Clarify datetime documentation for ISO8601 (GH-105049) (GH-114867)

(cherry picked from commit e9dab656380ec03d628979975646748330b76b9b)

Co-authored-by: Nicholas Hollander <31573882+nhhollander@users.noreply.github.com>

diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst
index 755f937f78a325d87f5fa35635f32fc09b4b67e7..922025acb036cbe452f5269f08fd7a925f1b5e0d 100644 (file)
--- a/Doc/library/datetime.rst
+++ b/Doc/library/datetime.rst
@@ -536,7 +536,15 @@ Other constructors, all class methods:
 .. classmethod:: date.fromisoformat(date_string)
 
    Return a :class:`date` corresponding to a *date_string* given in any valid
-   ISO 8601 format, except ordinal dates (e.g. ``YYYY-DDD``)::
+   ISO 8601 format, with the following exceptions:
+
+   1. Reduced precision dates are not currently supported (``YYYY-MM``,
+      ``YYYY``).
+   2. Extended date representations are not currently supported
+      (``±YYYYYY-MM-DD``).
+   3. Ordinal dates are not currently supported (``YYYY-OOO``).
+
+   Examples::
 
       >>> from datetime import date
       >>> date.fromisoformat('2019-12-04')
@@ -1006,8 +1014,12 @@ Other constructors, all class methods:
 
    1. Time zone offsets may have fractional seconds.
    2. The ``T`` separator may be replaced by any single unicode character.
-   3. Ordinal dates are not currently supported.
-   4. Fractional hours and minutes are not supported.
+   3. Fractional hours and minutes are not supported.
+   4. Reduced precision dates are not currently supported (``YYYY-MM``,
+      ``YYYY``).
+   5. Extended date representations are not currently supported
+      (``±YYYYYY-MM-DD``).
+   6. Ordinal dates are not currently supported (``YYYY-OOO``).
 
    Examples::