51 lines
1.1 KiB
Python
51 lines
1.1 KiB
Python
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# -*- coding: utf-8 -*-
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# This file is part of convertdate.
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# http://github.com/fitnr/convertdate
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# Licensed under the MIT license:
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# http://opensource.org/licenses/MIT
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# Copyright (c) 2016, fitnr <fitnr@fakeisthenewreal>
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from math import trunc
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from calendar import isleap
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from . import gregorian
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def to_jd(year, dayofyear):
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'''Return Julian day count of given ISO year, and day of year'''
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return gregorian.to_jd(year, 1, 1) + dayofyear - 1
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def from_jd(jd):
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return from_gregorian(*gregorian.from_jd(jd))
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def from_gregorian(year, month, day):
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m = month + 1
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if m <= 3:
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m = m + 12
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leap = isleap(year)
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t = (trunc(30.6 * m) + day - 122 + 59 + leap) % (365 + leap)
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return year, t
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def to_gregorian(year, dayofyear):
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leap = isleap(year)
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if dayofyear < 59 + leap:
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leap_adj = 0
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elif leap:
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leap_adj = 1
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else:
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leap_adj = 2
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month = trunc((((dayofyear - 1 + leap_adj) * 12) + 373) / 367)
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startofmonth = from_gregorian(year, month, 1)
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return year, month, dayofyear - startofmonth[1] + 1
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