Be consistent about ISO 8601

Doc/library/datetime.rst

@@ -527,7 +527,7 @@ 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:
+   ISO 8601 format:
 
       >>> from datetime import date
       >>> date.fromisoformat('2019-12-04')
@@ -995,7 +995,7 @@ Other constructors, all class methods:
 .. classmethod:: datetime.fromisoformat(date_string)
 
    Return a :class:`.datetime` corresponding to a *date_string* in any valid
-   ISO-8601 format, with the following exceptions:
+   ISO 8601 format, with the following exceptions:
 
    1. Time zone offsets may have fractional seconds.
    2. The `T` separator may be replaced by any single unicode character.
@@ -1768,7 +1768,7 @@ Other constructor:
 .. classmethod:: time.fromisoformat(time_string)
 
    Return a :class:`.time` corresponding to a *time_string* in any valid
-   ISO-8601 format, with the following exceptions:
+   ISO 8601 format, with the following exceptions:
 
    1. Time zone offsets may have fractional seconds.
    2. The leading `T`, normally required in cases where there may be ambiguity between

Lib/datetime.py

@@ -1538,7 +1538,7 @@ def fromisoformat(cls, time_string):
         if not isinstance(time_string, str):
             raise TypeError('fromisoformat: argument must be str')
 
-        # The spec actually requires that time-only ISO-8601 strings start with
+        # The spec actually requires that time-only ISO 8601 strings start with
         # T, but the extended format allows this to be omitted as long as there
         # is no ambiguity with date strings.
         time_string = time_string.removeprefix('T')

Modules/_datetimemodule.c

@@ -4640,7 +4640,7 @@ time_fromisoformat(PyObject *cls, PyObject *tstr) {
         goto invalid_string_error;
     }
 
-    // The spec actually requires that time-only ISO-8601 strings start with
+    // The spec actually requires that time-only ISO 8601 strings start with
     // T, but the extended format allows this to be omitted as long as there
     // is no ambiguity with date strings.
     if (*p == 'T') {
@@ -5269,7 +5269,7 @@ static PyObject *
 _sanitize_isoformat_str(PyObject *dtstr)
 {
     Py_ssize_t len = PyUnicode_GetLength(dtstr);
-    if (len < 7) {  // All valid ISO8601 strings are at least 7 characters long
+    if (len < 7) {  // All valid ISO 8601 strings are at least 7 characters long
         return NULL;
     }