) # Note: drops milliseconds
+# The code to compute easter on a given year was copied from dateutil (pip
+# install python-dateutil) and dumped in here to avoid a dependency. Dateutil
+# is an Apache 2.0 LICENSE open source project:
+
+# Copyright 2017- dateutil contributors (see AUTHORS file)
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+# http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# The above license applies to all contributions after 2017-12-01, as well as
+# all contributions that have been re-licensed (see AUTHORS file for the list of
+# contributors who have re-licensed their code).
+# --------------------------------------------------------------------------------
+# dateutil - Extensions to the standard Python datetime module.
+
+# Copyright (c) 2015- - dateutil contributors (see AUTHORS file)
+
+# All rights reserved.
+
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+
+# * Redistributions of source code must retain the above copyright notice,
+# this list of conditions and the following disclaimer.
+# * Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+# * Neither the name of the copyright holder nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# The above BSD License Applies to all code, even that also covered by Apache 2.0.
+
+EASTER_JULIAN = 1
+EASTER_ORTHODOX = 2
+EASTER_WESTERN = 3
+
+
+def easter(year, method=EASTER_WESTERN):
+ """
+ This method was ported from the work done by GM Arts,
+ on top of the algorithm by Claus Tondering, which was
+ based in part on the algorithm of Ouding (1940), as
+ quoted in "Explanatory Supplement to the Astronomical
+ Almanac", P. Kenneth Seidelmann, editor.
+
+ This algorithm implements three different Easter
+ calculation methods:
+
+ 1. Original calculation in Julian calendar, valid in
+ dates after 326 AD
+ 2. Original method, with date converted to Gregorian
+ calendar, valid in years 1583 to 4099
+ 3. Revised method, in Gregorian calendar, valid in
+ years 1583 to 4099 as well
+
+ These methods are represented by the constants:
+
+ * ``EASTER_JULIAN = 1``
+ * ``EASTER_ORTHODOX = 2``
+ * ``EASTER_WESTERN = 3``
+
+ The default method is method 3.
+
+ More about the algorithm may be found at:
+
+ `GM Arts: Easter Algorithms <http://www.gmarts.org/index.php?go=415>`_
+
+ and
+
+ `The Calendar FAQ: Easter <https://www.tondering.dk/claus/cal/easter.php>`_
+
+ """
+
+ if not (1 <= method <= 3):
+ raise ValueError("invalid method")
+
+ # g - Golden year - 1
+ # c - Century
+ # h - (23 - Epact) mod 30
+ # i - Number of days from March 21 to Paschal Full Moon
+ # j - Weekday for PFM (0=Sunday, etc)
+ # p - Number of days from March 21 to Sunday on or before PFM
+ # (-6 to 28 methods 1 & 3, to 56 for method 2)
+ # e - Extra days to add for method 2 (converting Julian
+ # date to Gregorian date)
+
+ y = year
+ g = y % 19
+ e = 0
+ if method < 3:
+ # Old method
+ i = (19 * g + 15) % 30
+ j = (y + y // 4 + i) % 7
+ if method == 2:
+ # Extra dates to convert Julian to Gregorian date
+ e = 10
+ if y > 1600:
+ e = e + y // 100 - 16 - (y // 100 - 16) // 4
+ else:
+ # New method
+ c = y // 100
+ h = (c - c // 4 - (8 * c + 13) // 25 + 19 * g + 15) % 30
+ i = h - (h // 28) * (1 - (h // 28) * (29 // (h + 1)) * ((21 - g) // 11))
+ j = (y + y // 4 + i + 2 - c + c // 4) % 7
+
+ # p can be from -6 to 56 corresponding to dates 22 March to 23 May
+ # (later dates apply to method 2, although 23 May never actually occurs)
+ p = i - j + e
+ d = 1 + (p + 27 + (p + 6) // 40) % 31
+ m = 3 + (p + 26) // 30
+ return datetime.date(int(y), int(m), int(d))
+
+
if __name__ == '__main__':
import doctest
('tomorrow', datetime.datetime(2021, 7, 3)),
('yesterday', datetime.datetime(2021, 7, 1)),
('21:30', datetime.datetime(2021, 7, 2, 21, 30, 0, 0)),
+ (
+ '21:30 EST',
+ datetime.datetime(2021, 7, 2, 21, 30, 0, 0, tzinfo=pytz.timezone('EST')),
+ ),
+ (
+ '21:30 -0500',
+ datetime.datetime(2021, 7, 2, 21, 30, 0, 0, tzinfo=pytz.timezone('EST')),
+ ),
('12:01am', datetime.datetime(2021, 7, 2, 0, 1, 0, 0)),
('12:02p', datetime.datetime(2021, 7, 2, 12, 2, 0, 0)),
('0:03', datetime.datetime(2021, 7, 2, 0, 3, 0, 0)),
projects / pyutils.git / commitdiff