61 lines
1.6 KiB
Python
61 lines
1.6 KiB
Python
|
# -*- coding: utf-8 -*-
|
||
|
|
|
||
|
|
# This file is part of convertdate.
|
||
|
|
# http://github.com/fitnr/convertdate
|
||
|
|
|
||
|
|
# Licensed under the MIT license:
|
||
|
|
# http://opensource.org/licenses/MIT
|
||
|
|
# Copyright (c) 2016, fitnr <fitnr@fakeisthenewreal>
|
||
|
|
from math import trunc
|
||
|
|
from .utils import ceil, jwday, monthcalendarhelper
|
||
|
|
from . import gregorian
|
||
|
|
|
||
|
|
EPOCH = 1948439.5
|
||
|
|
WEEKDAYS = ("al-'ahad", "al-'ithnayn",
|
||
|
|
"ath-thalatha'", "al-'arb`a'",
|
||
|
|
"al-khamis", "al-jum`a", "as-sabt")
|
||
|
|
|
||
|
|
HAS_29_DAYS = (2, 4, 6, 8, 10)
|
||
|
|
HAS_30_DAYS = (1, 3, 5, 7, 9, 11)
|
||
|
|
|
||
|
|
|
||
|
|
def leap(year):
|
||
|
|
'''Is a given year a leap year in the Islamic calendar'''
|
||
|
|
return (((year * 11) + 14) % 30) < 11
|
||
|
|
|
||
|
|
|
||
|
|
def to_jd(year, month, day):
|
||
|
|
'''Determine Julian day count from Islamic date'''
|
||
|
|
return (day + ceil(29.5 * (month - 1)) + (year - 1) * 354 + trunc((3 + (11 * year)) / 30) + EPOCH) - 1
|
||
|
|
|
||
|
|
|
||
|
|
def from_jd(jd):
|
||
|
|
'''Calculate Islamic date from Julian day'''
|
||
|
|
|
||
|
|
jd = trunc(jd) + 0.5
|
||
|
|
year = trunc(((30 * (jd - EPOCH)) + 10646) / 10631)
|
||
|
|
month = min(12, ceil((jd - (29 + to_jd(year, 1, 1))) / 29.5) + 1)
|
||
|
|
day = int(jd - to_jd(year, month, 1)) + 1
|
||
|
|
return (year, month, day)
|
||
|
|
|
||
|
|
|
||
|
|
def from_gregorian(year, month, day):
|
||
|
|
return from_jd(gregorian.to_jd(year, month, day))
|
||
|
|
|
||
|
|
|
||
|
|
def to_gregorian(year, month, day):
|
||
|
|
return gregorian.from_jd(to_jd(year, month, day))
|
||
|
|
|
||
|
|
|
||
|
|
def month_length(year, month):
|
||
|
|
if month in HAS_30_DAYS or (month == 12 and leap(year)):
|
||
|
|
return 30
|
||
|
|
|
||
|
|
return 29
|
||
|
|
|
||
|
|
|
||
|
|
def monthcalendar(year, month):
|
||
|
|
start_weekday = jwday(to_jd(year, month, 1))
|
||
|
|
monthlen = month_length(year, month)
|
||
|
|
return monthcalendarhelper(start_weekday, monthlen)
|