Opa_omroep-automatiseren/venv/lib/python3.8/site-packages/convertdate/persian.py
Eljakim Herrewijnen f26bbbf103 initial
2020-12-27 21:00:11 +01:00

103 lines
2.4 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 = 1948320.5
WEEKDAYS = ("Doshanbeh", "Seshhanbeh",
"Chaharshanbeh", "Panjshanbeh",
"Jomeh", "Shanbeh", "Yekshanbeh")
HAS_31_DAYS = (1, 2, 3, 4, 5, 6)
HAS_30_DAYS = (7, 8, 9, 10, 11)
def leap(year):
'''Is a given year a leap year in the Persian calendar ?'''
if year > 0:
y = 474
else:
y = 473
return ((((((year - y % 2820) + 474) + 38) * 682) % 2816) < 682)
def to_jd(year, month, day):
'''Determine Julian day from Persian date'''
if year >= 0:
y = 474
else:
y = 473
epbase = year - y
epyear = 474 + (epbase % 2820)
if month <= 7:
m = (month - 1) * 31
else:
m = (month - 1) * 30 + 6
return day + m + trunc(((epyear * 682) - 110) / 2816) + (epyear - 1) * 365 + trunc(epbase / 2820) * 1029983 + (EPOCH - 1)
def from_jd(jd):
'''Calculate Persian date from Julian day'''
jd = trunc(jd) + 0.5
depoch = jd - to_jd(475, 1, 1)
cycle = trunc(depoch / 1029983)
cyear = (depoch % 1029983)
if cyear == 1029982:
ycycle = 2820
else:
aux1 = trunc(cyear / 366)
aux2 = cyear % 366
ycycle = trunc(((2134 * aux1) + (2816 * aux2) + 2815) / 1028522) + aux1 + 1
year = ycycle + (2820 * cycle) + 474
if (year <= 0):
year -= 1
yday = (jd - to_jd(year, 1, 1)) + 1
if yday <= 186:
month = ceil(yday / 31)
else:
month = ceil((yday - 6) / 30)
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
elif month in HAS_31_DAYS:
return 31
return 29
def monthcalendar(year, month):
start_weekday = jwday(to_jd(year, month, 1))
monthlen = month_length(year, month)
return monthcalendarhelper(start_weekday, monthlen)