diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst
@@ -428,6 +428,19 @@ Other constructors, all class methods:
      :exc:`ValueError` on :c:func:`localtime` failure.


.. classmethod:: date.fromordinal(ordinal)

   Return the date corresponding to the proleptic Gregorian ordinal, where January
@@ -793,6 +806,19 @@ Other constructors, all class methods:
      :exc:`ValueError` on :c:func:`gmtime` failure.


.. classmethod:: datetime.fromordinal(ordinal)

   Return the :class:`.datetime` corresponding to the proleptic Gregorian ordinal,
@@ -1394,6 +1420,22 @@ day, and subject to adjustment via a :class:`tzinfo` object.
   If an argument outside those ranges is given, :exc:`ValueError` is raised.  All
   default to ``0`` except *tzinfo*, which defaults to :const:`None`.

Class attributes:



diff --git a/Lib/_strptime.py b/Lib/_strptime.py
@@ -14,7 +14,7 @@
import locale
import calendar
from re import compile as re_compile
-from re import IGNORECASE
from re import escape as re_escape
from datetime import (date as datetime_date,
                      timedelta as datetime_timedelta,
@@ -27,6 +27,55 @@ def _getlang():
    # Figure out what the current language is set to.
    return locale.getlocale(locale.LC_TIME)

class LocaleTime(object):
    """Stores and handles locale-specific information related to time.


diff --git a/Lib/datetime.py b/Lib/datetime.py
@@ -732,6 +732,15 @@ def fromordinal(cls, n):
        y, m, d = _ord2ymd(n)
        return cls(y, m, d)

    # Conversions to string

    def __repr__(self):
@@ -1075,6 +1084,16 @@ def __new__(cls, hour=0, minute=0, second=0, microsecond=0, tzinfo=None, *, fold
        self._fold = fold
        return self

    # Read-only field accessors
    @property
    def hour(self):
@@ -1472,6 +1491,16 @@ def utcfromtimestamp(cls, t):
        """Construct a naive UTC datetime from a POSIX timestamp."""
        return cls._fromtimestamp(t, True, None)

    @classmethod
    def now(cls, tz=None):
        "Construct a datetime from time.time() and optional time zone info."

diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py
@@ -1166,6 +1166,19 @@ def test_fromtimestamp(self):
        self.assertEqual(d.month, month)
        self.assertEqual(d.day, day)

    def test_insane_fromtimestamp(self):
        # It's possible that some platform maps time_t to double,
        # and that this test will fail there.  This test should
@@ -1976,6 +1989,18 @@ def test_utcfromtimestamp(self):
        got = self.theclass.utcfromtimestamp(ts)
        self.verify_field_equality(expected, got)

    # Run with US-style DST rules: DST begins 2 a.m. on second Sunday in
    # March (M3.2.0) and ends 2 a.m. on first Sunday in November (M11.1.0).
    @support.run_with_tz('EST+05EDT,M3.2.0,M11.1.0')
@@ -2517,6 +2542,42 @@ def test_isoformat(self):
        self.assertEqual(t.isoformat(timespec='microseconds'), "12:34:56.000000")
        self.assertEqual(t.isoformat(timespec='auto'), "12:34:56")

    def test_1653736(self):
        # verify it doesn't accept extra keyword arguments
        t = self.theclass(second=1)

diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
@@ -2607,6 +2607,25 @@ date_fromtimestamp(PyObject *cls, PyObject *args)
    return result;
}

/* Return new date from proleptic Gregorian ordinal.  Raises ValueError if
 * the ordinal is out of range.
 */
@@ -2920,6 +2939,11 @@ static PyMethodDef date_methods[] = {
     PyDoc_STR("timestamp -> local date from a POSIX timestamp (like "
               "time.time()).")},

    {"fromordinal", (PyCFunction)date_fromordinal,      METH_VARARGS |
                                                    METH_CLASS,
     PyDoc_STR("int -> date corresponding to a proleptic Gregorian "
@@ -3711,6 +3735,26 @@ time_str(PyDateTime_Time *self)
    return _PyObject_CallMethodId((PyObject *)self, &PyId_isoformat, NULL);
}

static PyObject *
time_isoformat(PyDateTime_Time *self, PyObject *args, PyObject *kw)
{
@@ -4018,6 +4062,13 @@ time_reduce(PyDateTime_Time *self, PyObject *arg)

static PyMethodDef time_methods[] = {

    {"isoformat",   (PyCFunction)time_isoformat,        METH_VARARGS | METH_KEYWORDS,
     PyDoc_STR("Return string in ISO 8601 format, [HH[:MM[:SS[.mmm[uuu]]]]]"
               "[+HH:MM].\n\n"
@@ -4726,6 +4777,25 @@ datetime_str(PyDateTime_DateTime *self)
    return _PyObject_CallMethodId((PyObject *)self, &PyId_isoformat, "s", " ");
}

static PyObject *
datetime_isoformat(PyDateTime_DateTime *self, PyObject *args, PyObject *kw)
{
@@ -5506,6 +5576,12 @@ static PyMethodDef datetime_methods[] = {
     METH_VARARGS | METH_KEYWORDS | METH_CLASS,
     PyDoc_STR("timestamp[, tz] -> tz's local time from POSIX timestamp.")},

    {"utcfromtimestamp", (PyCFunction)datetime_utcfromtimestamp,
     METH_VARARGS | METH_CLASS,
     PyDoc_STR("Construct a naive UTC datetime from a POSIX timestamp.")},