def datetime(
year, month, day, hour=0, minute=0, second=0, microsecond=0,
tzinfo=None, calendar='proleptic_gregorian'):
"""
Retrieves a datetime-like object with the requested calendar. Calendar types
other than proleptic_gregorian require the netcdftime module to be
installed.
Parameters
----------
year : int,
month : int,
day : int,
hour : int, optional
minute : int, optional
second : int, optional
microsecond : int, optional
tzinfo : datetime.tzinfo, optional
A timezone informaton class, such as from pytz. Can only be used with
'proleptic_gregorian' calendar, as netcdftime does not support
timezones.
calendar : string, optional
Should be one of 'proleptic_gregorian', 'no_leap', '365_day',
'all_leap', '366_day', '360_day', 'julian', or 'gregorian'. Default
is 'proleptic_gregorian', which returns a normal Python datetime.
Other options require the netcdftime module to be installed.
Returns
-------
datetime : datetime-like
The requested datetime. May be a Python datetime, or one of the
datetime-like types in netcdftime.
"""
kwargs = {
'year': year, 'month': month, 'day': day, 'hour': hour,
'minute': minute, 'second': second, 'microsecond': microsecond
}
if calendar.lower() == 'proleptic_gregorian':
return real_datetime(tzinfo=tzinfo, **kwargs)
elif tzinfo is not None:
raise ValueError('netcdftime does not support timezone-aware datetimes')
elif nt is None:
raise DependencyError(
"Calendars other than 'proleptic_gregorian' require the netcdftime "
"package, which is not installed.")
elif calendar.lower() in ('all_leap', '366_day'):
return nt.DatetimeAllLeap(**kwargs)
elif calendar.lower() in ('no_leap', 'noleap', '365_day'):
return nt.DatetimeNoLeap(**kwargs)
elif calendar.lower() == '360_day':
return nt.Datetime360Day(**kwargs)
elif calendar.lower() == 'julian':
return nt.DatetimeJulian(**kwargs)
elif calendar.lower() == 'gregorian':
return nt.DatetimeGregorian(**kwargs)
def parse_date(raw_date):
"""Get the date in correct format using dateutil.parser.
Note that if no month or day can be found in the raw date string, they
will be set to 1 (e.g., "Mar 1999" -> "1999-03-01"). If the string cannot
be parsed, return the string.
"""
if not raw_date:
return raw_date
if not isinstance(raw_date, str):
raw_date = str(raw_date)
try:
DEFAULT_DATE = real_datetime(1, 1, 1)
parsed_date = dparser.parse(raw_date, default=DEFAULT_DATE)
date_published = parsed_date.date().isoformat()
except ValueError:
date_published = raw_date
return date_published
def parse_date(raw_date):
"""Get the date in correct format using dateutil.parser.
Note that if no month or day can be found in the raw date string, they
will be set to 1 (e.g., "Mar 1999" -> "1999-03-01"). If the string cannot
be parsed, return the string.
"""
if not raw_date:
return raw_date
if not isinstance(raw_date, str):
raw_date = str(raw_date)
try:
DEFAULT_DATE = real_datetime(1, 1, 1)
parsed_date = dparser.parse(raw_date, default=DEFAULT_DATE)
date_published = parsed_date.date().isoformat()
except ValueError:
date_published = raw_date
return date_published
def closest_date(date, date_from, date_to):
"""
Adjusts year so that the date is closest to the given range.
Transactions dates in a statement usually contain only day and month.
Statement dates range have a year though.
Merge them all together to get a full transaction date.
"""
# If the date is within given range, we're done.
if date_from <= date <= date_to:
return date
dates = [real_datetime(year, date.month, date.day)
for year in xrange(date_from.year, date_to.year+1)]
# Ideally, pick the date within given range.
for d in dates:
if date_from <= d <= date_to:
return d
# Otherwise, return the most recent date in the past.
return min(dates, key=lambda d: abs(d-date_from))
def closest_date(date, date_from, date_to):
"""
Adjusts year so that the date is closest to the given range.
Transactions dates in a statement usually contain only day and month.
Statement dates range have a year though.
Merge them all together to get a full transaction date.
"""
# If the date is within given range, we're done.
if date_from <= date <= date_to:
return date
dates = [real_datetime(year, date.month, date.day)
for year in xrange(date_from.year, date_to.year+1)]
# Ideally, pick the date within given range.
for d in dates:
if date_from <= d <= date_to:
return d
# Otherwise, return the most recent date in the past.
return min(dates, key=lambda d: abs(d-date_from))
def setUp(self):
from datetime import datetime as real_datetime
self.hour_before = real_datetime(2013, 1, 1, 9, 30, 0, 0)
self.minute_before = real_datetime(2013, 1, 1, 10, 29, 0, 0)
self.now = real_datetime(2013, 1, 1, 10, 30, 0, 0)
def strptime(date_string, fmt):
"""A strptime(date string, format) that support dates before 1900."""
return real_datetime(*(time.strptime(date_string, fmt)[:6]))
def strptime(date_string, fmt):
return real_datetime(*(time.strptime(date_string, fmt)[:6]))
def strptime(date_string, fmt):
return real_datetime(*(time.strptime(date_string, fmt)[:6]))
def DateFromJulianDate(JD, calendar='standard'):
"""
Algorithm:
Meeus, Jean (1998) Astronomical Algorithms (2nd Edition). Willmann-Bell,
Virginia. p. 63
"""
if JD < 0:
raise ValueError('Julian Day must be positive')
dayofwk = int(math.fmod(int(JD + 1.5), 7))
(F, Z) = math.modf(JD + 0.5)
Z = int(Z)
if calendar in ['standard', 'gregorian']:
if JD < 2299160.5:
A = Z
else:
alpha = int((Z - 1867216.25) / 36524.25)
A = Z + 1 + alpha - int(alpha / 4)
elif calendar == 'proleptic_gregorian':
alpha = int((Z - 1867216.25) / 36524.25)
A = Z + 1 + alpha - int(alpha / 4)
elif calendar == 'julian':
A = Z
else:
raise ValueError(
'unknown calendar, must be one of julian,standard,gregorian,proleptic_gregorian, got %s'
% calendar)
B = A + 1524
C = int((B - 122.1) / 365.25)
D = int(365.25 * C)
E = int((B - D) / 30.6001)
# Convert to date
day = B - D - int(30.6001 * E) + F
nday = B - D - 123
if nday <= 305:
dayofyr = nday + 60
else:
dayofyr = nday - 305
if E < 14:
month = E - 1
else:
month = E - 13
if month > 2:
year = C - 4716
else:
year = C - 4715
# a leap year?
leap = 0
if year % 4 == 0:
leap = 1
if calendar == 'proleptic_gregorian' or \
(calendar in ['standard','gregorian'] and JD >= 2299160.5):
if year % 100 == 0 and year % 400 != 0:
leap = 0
if leap and month > 2:
dayofyr = dayofyr + leap
# Convert fractions of a day to time
(dfrac, days) = math.modf(day / 1.0)
(hfrac, hours) = math.modf(dfrac * 24.0)
(mfrac, minutes) = math.modf(hfrac * 60.0)
seconds = round(mfrac * 60.0) # seconds are rounded
if seconds > 59:
seconds = 0
minutes = minutes + 1
if minutes > 59:
minutes = 0
hours = hours + 1
if hours > 23:
hours = 0
days = days + 1
daysinmonth = monthrange(year, month)[1]
if days > daysinmonth:
days = 1
month = month + 1
if month > 12:
month = 1
year = year + 1
# return a 'real' datetime instance if calendar is gregorian.
if calendar == 'proleptic_gregorian' or \
(calendar in ['standard','gregorian'] and JD >= 2299160.5):
return real_datetime(year, month, int(days), int(hours),
int(minutes), int(seconds))
else:
# or else, return a 'datetime-like' instance.
return datetime(year, month, int(days), int(hours), int(minutes),
int(seconds), dayofwk, dayofyr)
def DateFromJulianDay(JD,calendar='standard'):
"""
returns a 'datetime-like' object given Julian Day. Julian Day is a
fractional day with a resolution of 1 second.
if calendar='standard' or 'gregorian' (default), Julian day follows Julian
Calendar on and before 1582-10-5, Gregorian calendar after 1582-10-15.
if calendar='proleptic_gregorian', Julian Day follows gregorian calendar.
if calendar='julian', Julian Day follows julian calendar.
The datetime object is a 'real' datetime object if the date falls in
the Gregorian calendar (i.e. calendar='proleptic_gregorian', or
calendar = 'standard'/'gregorian' and the date is after 1582-10-15).
Otherwise, it's a 'phony' datetime object which is actually an instance
of netcdftime.datetime.
Algorithm:
Meeus, Jean (1998) Astronomical Algorithms (2nd Edition). Willmann-Bell,
Virginia. p. 63
"""
# based on redate.py by David Finlayson.
if JD < 0:
raise ValueError('Julian Day must be positive')
dayofwk = int(math.fmod(int(JD + 1.5),7))
(F, Z) = math.modf(JD + 0.5)
Z = int(Z)
if calendar in ['standard','gregorian']:
if JD < 2299160.5:
A = Z
else:
# MC
# alpha = int((Z - 1867216.25)/36524.25)
# A = Z + 1 + alpha - int(alpha/4)
alpha = int(((Z - 1867216.)-0.25)/36524.25)
A = Z + 1 + alpha - int(0.25*alpha)
elif calendar == 'proleptic_gregorian':
# MC
# alpha = int((Z - 1867216.25)/36524.25)
# A = Z + 1 + alpha - int(alpha/4)
alpha = int(((Z - 1867216.)-0.25)/36524.25)
A = Z + 1 + alpha - int(0.25*alpha)
elif calendar == 'julian':
A = Z
else:
raise ValueError('unknown calendar, must be one of julian,standard,gregorian,proleptic_gregorian, got %s' % calendar)
B = A + 1524
# MC
# C = int((B - 122.1)/365.25)
# D = int(365.25 * C)
C = int(6680.+((B-2439870.)-122.1)/365.25)
D = 365*C + int(0.25 * C)
E = int((B - D)/30.6001)
# Convert to date
day = B - D - int(30.6001 * E) + F
nday = B-D-123
if nday <= 305:
dayofyr = nday+60
else:
dayofyr = nday-305
# MC
# if E < 14:
# month = E - 1
# else:
# month = E - 13
# if month > 2:
# year = C - 4716
# else:
# year = C - 4715
month = E - 1
if month > 12: month -= 12
year = C - 4715
if month > 2: year -= 1
if year <= 0: year -= 1
# a leap year?
leap = 0
if year % 4 == 0:
leap = 1
if calendar == 'proleptic_gregorian' or \
(calendar in ['standard','gregorian'] and JD >= 2299160.5):
if year % 100 == 0 and year % 400 != 0:
leap = 0
if leap and month > 2:
dayofyr = dayofyr + leap
# Convert fractions of a day to time
(dfrac, days) = math.modf(day/1.0)
(hfrac, hours) = math.modf(dfrac * 24.0)
(mfrac, minutes) = math.modf(hfrac * 60.0)
seconds = round(mfrac * 60.0) # seconds are rounded
if seconds > 59:
seconds = 0
minutes = minutes + 1
if minutes > 59:
minutes = 0
hours = hours + 1
if hours > 23:
hours = 0
days = days + 1
# if days exceeds number allowed in a month, flip to next month.
# this fixes issue 75.
daysinmonth = monthrange(year, month)[1]
if days > daysinmonth:
days = 1
month = month + 1
if month > 12:
month = 1
year = year + 1
# return a 'real' datetime instance if calendar is gregorian.
if calendar == 'proleptic_gregorian' or \
(calendar in ['standard','gregorian'] and JD >= 2299160.5):
return real_datetime(year,month,int(days),int(hours),int(minutes),int(seconds))
else:
# or else, return a 'datetime-like' instance.
return datetime(year,month,int(days),int(hours),int(minutes),int(seconds),dayofwk,dayofyr)
def DateFromJulianDay(JD, calendar='standard'):
"""
returns a 'datetime-like' object given Julian Day. Julian Day is a
fractional day with a resolution of approximately 0.1 seconds.
if calendar='standard' or 'gregorian' (default), Julian day follows Julian
Calendar on and before 1582-10-5, Gregorian calendar after 1582-10-15.
if calendar='proleptic_gregorian', Julian Day follows gregorian calendar.
if calendar='julian', Julian Day follows julian calendar.
The datetime object is a 'real' datetime object if the date falls in
the Gregorian calendar (i.e. calendar='proleptic_gregorian', or
calendar = 'standard'/'gregorian' and the date is after 1582-10-15).
Otherwise, it's a 'phony' datetime object which is actually an instance
of netcdftime.datetime.
Algorithm:
Meeus, Jean (1998) Astronomical Algorithms (2nd Edition). Willmann-Bell,
Virginia. p. 63
"""
# based on redate.py by David Finlayson.
julian = np.array(JD, dtype=float)
if np.min(julian) < 0:
raise ValueError('Julian Day must be positive')
dayofwk = np.atleast_1d(np.int32(np.fmod(np.int32(julian + 1.5), 7)))
# get the day (Z) and the fraction of the day (F)
# add 0.000005 which is 452 ms in case of jd being after
# second 23:59:59 of a day we want to round to the next day see issue #75
Z = np.atleast_1d(np.int32(np.round(julian + 0.00005)))
F = np.atleast_1d(julian + 0.5 - Z).astype(np.float64)
if calendar in ['standard', 'gregorian']:
# MC
# alpha = int((Z - 1867216.25)/36524.25)
# A = Z + 1 + alpha - int(alpha/4)
alpha = np.int32(((Z - 1867216.) - 0.25) / 36524.25)
A = Z + 1 + alpha - np.int32(0.25 * alpha)
# check if dates before oct 5th 1582 are in the array
ind_before = np.where(julian < 2299160.5)[0]
if len(ind_before) > 0:
A[ind_before] = Z[ind_before]
elif calendar == 'proleptic_gregorian':
# MC
# alpha = int((Z - 1867216.25)/36524.25)
# A = Z + 1 + alpha - int(alpha/4)
alpha = np.int32(((Z - 1867216.) - 0.25) / 36524.25)
A = Z + 1 + alpha - np.int32(0.25 * alpha)
elif calendar == 'julian':
A = Z
else:
raise ValueError(
'unknown calendar, must be one of julian,standard,gregorian,proleptic_gregorian, got %s' % calendar)
B = A + 1524
# MC
# C = int((B - 122.1)/365.25)
# D = int(365.25 * C)
C = np.atleast_1d(np.int32(6680. + ((B - 2439870.) - 122.1) / 365.25))
D = np.atleast_1d(np.int32(365 * C + np.int32(0.25 * C)))
E = np.atleast_1d(np.int32((B - D) / 30.6001))
# Convert to date
day = np.clip(B - D - np.int64(30.6001 * E) + F, 1, None)
nday = B - D - 123
dayofyr = nday - 305
ind_nday_before = np.where(nday <= 305)[0]
if len(ind_nday_before) > 0:
dayofyr[ind_nday_before] = nday[ind_nday_before] + 60
# MC
# if E < 14:
# month = E - 1
# else:
# month = E - 13
# if month > 2:
# year = C - 4716
# else:
# year = C - 4715
month = E - 1
month[month > 12] = month[month > 12] - 12
year = C - 4715
year[month > 2] = year[month > 2] - 1
year[year <= 0] = year[year <= 0] - 1
# a leap year?
leap = np.zeros(len(year),dtype=dayofyr.dtype)
leap[year % 4 == 0] = 1
if calendar == 'proleptic_gregorian':
leap[(year % 100 == 0) & (year % 400 != 0)] = 0
elif calendar in ['standard', 'gregorian']:
leap[(year % 100 == 0) & (year % 400 != 0) & (julian < 2299160.5)] = 0
inc_idx = np.where((leap == 1) & (month > 2))[0]
dayofyr[inc_idx] = dayofyr[inc_idx] + leap[inc_idx]
eps = np.clip(
(1e-12 * np.abs(Z)).astype(np.float64), np.float64(1e-12), None)
hour = np.clip((F * 24. + eps).astype(np.int64), 0, 23)
F -= hour / 24.
minute = np.clip((F * 1440. + eps).astype(np.int64), 0, 59)
second = np.clip((F - minute / 1440.) * 86400., 0, None)
# microseconds may not be accurate.
microsecond = (second % 1)*1.e6
# convert year, month, day, hour, minute, second to int32
year = year.astype(np.int32)
month = month.astype(np.int32)
day = day.astype(np.int32)
hour = hour.astype(np.int32)
minute = minute.astype(np.int32)
second = second.astype(np.int32)
microsecond = microsecond.astype(np.int32)
# check if input was scalar and change return accordingly
isscalar = False
try:
JD[0]
except:
isscalar = True
# return a 'real' datetime instance if calendar is gregorian.
if calendar in 'proleptic_gregorian' or \
(calendar in ['standard', 'gregorian'] and len(ind_before) == 0):
if not isscalar:
return np.array([real_datetime(*args)
for args in
zip(year, month, day, hour, minute, second,
microsecond)])
else:
return real_datetime(year[0], month[0], day[0], hour[0],
minute[0], second[0], microsecond[0])
else:
# or else, return a 'datetime-like' instance.
if not isscalar:
return np.array([datetime(*args)
for args in
zip(year, month, day, hour, minute,
second, microsecond, dayofwk, dayofyr)])
else:
return datetime(year[0], month[0], day[0], hour[0],
minute[0], second[0], microsecond[0], dayofwk[0],
dayofyr[0])
def _to_real_datetime(self):
return real_datetime(self._year, self._month, self._day, self._hour, self._minute, self._second)
def DateFromJulianDay(JD, calendar='standard'):
"""
returns a 'datetime-like' object given Julian Day. Julian Day is a
fractional day with a resolution of 1 second.
if calendar='standard' or 'gregorian' (default), Julian day follows Julian
Calendar on and before 1582-10-5, Gregorian calendar after 1582-10-15.
if calendar='proleptic_gregorian', Julian Day follows gregorian calendar.
if calendar='julian', Julian Day follows julian calendar.
The datetime object is a 'real' datetime object if the date falls in
the Gregorian calendar (i.e. calendar='proleptic_gregorian', or
calendar = 'standard'/'gregorian' and the date is after 1582-10-15).
Otherwise, it's a 'phony' datetime object which is actually an instance
of netcdftime.datetime.
Algorithm:
Meeus, Jean (1998) Astronomical Algorithms (2nd Edition). Willmann-Bell,
Virginia. p. 63
"""
# based on redate.py by David Finlayson.
if JD < 0:
raise ValueError('Julian Day must be positive')
dayofwk = int(math.fmod(int(JD + 1.5), 7))
(F, Z) = math.modf(JD + 0.5)
Z = int(Z)
if calendar in ['standard', 'gregorian']:
if JD < 2299160.5:
A = Z
else:
# MC
# alpha = int((Z - 1867216.25)/36524.25)
# A = Z + 1 + alpha - int(alpha/4)
alpha = int(((Z - 1867216.) - 0.25) / 36524.25)
A = Z + 1 + alpha - int(0.25 * alpha)
elif calendar == 'proleptic_gregorian':
# MC
# alpha = int((Z - 1867216.25)/36524.25)
# A = Z + 1 + alpha - int(alpha/4)
alpha = int(((Z - 1867216.) - 0.25) / 36524.25)
A = Z + 1 + alpha - int(0.25 * alpha)
elif calendar == 'julian':
A = Z
else:
raise ValueError(
'unknown calendar, must be one of julian,standard,gregorian,proleptic_gregorian, got %s'
% calendar)
B = A + 1524
# MC
# C = int((B - 122.1)/365.25)
# D = int(365.25 * C)
C = int(6680. + ((B - 2439870.) - 122.1) / 365.25)
D = 365 * C + int(0.25 * C)
E = int((B - D) / 30.6001)
# Convert to date
day = B - D - int(30.6001 * E) + F
nday = B - D - 123
if nday <= 305:
dayofyr = nday + 60
else:
dayofyr = nday - 305
# MC
# if E < 14:
# month = E - 1
# else:
# month = E - 13
# if month > 2:
# year = C - 4716
# else:
# year = C - 4715
month = E - 1
if month > 12: month -= 12
year = C - 4715
if month > 2: year -= 1
if year <= 0: year -= 1
# a leap year?
leap = 0
if year % 4 == 0:
leap = 1
if calendar == 'proleptic_gregorian' or \
(calendar in ['standard','gregorian'] and JD >= 2299160.5):
if year % 100 == 0 and year % 400 != 0:
leap = 0
if leap and month > 2:
dayofyr = dayofyr + leap
# Convert fractions of a day to time
(dfrac, days) = math.modf(day / 1.0)
(hfrac, hours) = math.modf(dfrac * 24.0)
(mfrac, minutes) = math.modf(hfrac * 60.0)
seconds = round(mfrac * 60.0) # seconds are rounded
if seconds > 59:
seconds = 0
minutes = minutes + 1
if minutes > 59:
minutes = 0
hours = hours + 1
if hours > 23:
hours = 0
days = days + 1
# if days exceeds number allowed in a month, flip to next month.
# this fixes issue 75.
daysinmonth = monthrange(year, month)[1]
if days > daysinmonth:
days = 1
month = month + 1
if month > 12:
month = 1
year = year + 1
# return a 'real' datetime instance if calendar is gregorian.
if calendar == 'proleptic_gregorian' or \
(calendar in ['standard','gregorian'] and JD >= 2299160.5):
return real_datetime(year, month, int(days), int(hours), int(minutes),
int(seconds))
else:
# or else, return a 'datetime-like' instance.
return datetime(year, month, int(days), int(hours), int(minutes),
int(seconds), dayofwk, dayofyr)
def setUp(self):
from datetime import datetime as real_datetime
self.hour_before = real_datetime(2013, 1, 1, 9, 30, 0, 0)
self.minute_before = real_datetime(2013, 1, 1, 10, 29, 0, 0)
self.now = real_datetime(2013, 1, 1, 10, 30, 0, 0)
def DateFromJulianDay(JD, calendar='standard'):
"""
returns a 'datetime-like' object given Julian Day. Julian Day is a
fractional day with a resolution of 1 second.
if calendar='standard' or 'gregorian' (default), Julian day follows Julian
Calendar on and before 1582-10-5, Gregorian calendar after 1582-10-15.
if calendar='proleptic_gregorian', Julian Day follows gregorian calendar.
if calendar='julian', Julian Day follows julian calendar.
The datetime object is a 'real' datetime object if the date falls in
the Gregorian calendar (i.e. calendar='proleptic_gregorian', or
calendar = 'standard'/'gregorian' and the date is after 1582-10-15).
Otherwise, it's a 'phony' datetime object which is actually an instance
of netcdftime.datetime.
Algorithm:
Meeus, Jean (1998) Astronomical Algorithms (2nd Edition). Willmann-Bell,
Virginia. p. 63
"""
# based on redate.py by David Finlayson.
julian = np.array(JD, dtype=float)
if np.min(julian) < 0:
raise ValueError('Julian Day must be positive')
dayofwk = np.atleast_1d(np.int32(np.fmod(np.int32(julian + 1.5), 7)))
# get the day (Z) and the fraction of the day (F)
# add 0.000005 which is 452 ms in case of jd being after
# second 23:59:59 of a day we want to round to the next day see issue #75
Z = np.atleast_1d(np.int32(np.round(julian + 0.00005)))
F = np.atleast_1d(julian + 0.5 - Z).astype(np.float64)
if calendar in ['standard', 'gregorian']:
# MC
# alpha = int((Z - 1867216.25)/36524.25)
# A = Z + 1 + alpha - int(alpha/4)
alpha = np.int32(((Z - 1867216.) - 0.25) / 36524.25)
A = Z + 1 + alpha - np.int32(0.25 * alpha)
# check if dates before oct 5th 1582 are in the array
ind_before = np.where(julian < 2299160.5)[0]
if len(ind_before) > 0:
A[ind_before] = Z[ind_before]
elif calendar == 'proleptic_gregorian':
# MC
# alpha = int((Z - 1867216.25)/36524.25)
# A = Z + 1 + alpha - int(alpha/4)
alpha = np.int32(((Z - 1867216.) - 0.25) / 36524.25)
A = Z + 1 + alpha - np.int32(0.25 * alpha)
elif calendar == 'julian':
A = Z
else:
raise ValueError(
'unknown calendar, must be one of julian,standard,gregorian,proleptic_gregorian, got %s'
% calendar)
B = A + 1524
# MC
# C = int((B - 122.1)/365.25)
# D = int(365.25 * C)
C = np.atleast_1d(np.int32(6680. + ((B - 2439870.) - 122.1) / 365.25))
D = np.atleast_1d(np.int32(365 * C + np.int32(0.25 * C)))
E = np.atleast_1d(np.int32((B - D) / 30.6001))
# Convert to date
day = np.clip(B - D - np.int64(30.6001 * E) + F, 1, None)
nday = B - D - 123
dayofyr = nday - 305
ind_nday_before = np.where(nday <= 305)[0]
if len(ind_nday_before) > 0:
dayofyr[ind_nday_before] = nday[ind_nday_before] + 60
# MC
# if E < 14:
# month = E - 1
# else:
# month = E - 13
# if month > 2:
# year = C - 4716
# else:
# year = C - 4715
month = E - 1
month[month > 12] = month[month > 12] - 12
year = C - 4715
year[month > 2] = year[month > 2] - 1
year[year <= 0] = year[year <= 0] - 1
# a leap year?
leap = np.zeros(len(year))
leap[year % 4 == 0] = 1
if calendar == 'proleptic_gregorian':
leap[(year % 100 == 0) & (year % 400 != 0)] = 0
elif calendar in ['standard', 'gregorian']:
leap[(year % 100 == 0) & (year % 400 != 0) & (julian < 2299160.5)] = 0
inc_idx = np.where((leap == 1) & (month > 2))[0]
dayofyr[inc_idx] = dayofyr[inc_idx] + leap[inc_idx]
eps = np.clip((1e-12 * np.abs(Z)).astype(np.float64), np.float64(1e-12),
None)
hour = np.clip((F * 24. + eps).astype(np.int64), 0, 23)
F -= hour / 24.
minute = np.clip((F * 1440. + eps).astype(np.int64), 0, 59)
# don't attempt microsecond accuracy, just round to nearest
# second (issue #330)
second = np.round(np.clip((F - minute / 1440.) * 86400., 0, None))
# convert year, month, day, hour, minute, second to int32
year = year.astype(np.int32)
month = month.astype(np.int32)
day = day.astype(np.int32)
hour = hour.astype(np.int32)
minute = minute.astype(np.int32)
second = second.astype(np.int32)
# check if input was scalar and change return accordingly
isscalar = False
try:
JD[0]
except:
isscalar = True
# return a 'real' datetime instance if calendar is gregorian.
if calendar in 'proleptic_gregorian' or \
(calendar in ['standard', 'gregorian'] and len(ind_before) == 0):
if not isscalar:
return np.array([
real_datetime(*args)
for args in zip(year, month, day, hour, minute, second)
])
else:
return real_datetime(year[0], month[0], day[0], hour[0], minute[0],
second[0])
else:
# or else, return a 'datetime-like' instance.
if not isscalar:
return np.array([
datetime(*args) for args in zip(year, month, day, hour, minute,
second, dayofwk, dayofyr)
])
else:
return datetime(year[0], month[0], day[0], hour[0], minute[0],
second[0], dayofwk[0], dayofyr[0])
def DateFromJulianDay(JD, calendar="standard"):
"""
returns a 'datetime-like' object given Julian Day. Julian Day is a
fractional day with a resolution of 1 second.
if calendar='standard' or 'gregorian' (default), Julian day follows Julian
Calendar on and before 1582-10-5, Gregorian calendar after 1582-10-15.
if calendar='proleptic_gregorian', Julian Day follows gregorian calendar.
if calendar='julian', Julian Day follows julian calendar.
The datetime object is a 'real' datetime object if the date falls in
the Gregorian calendar (i.e. calendar='proleptic_gregorian', or
calendar = 'standard'/'gregorian' and the date is after 1582-10-15).
Otherwise, it's a 'phony' datetime object which is actually an instance
of netcdftime.datetime.
Algorithm:
Meeus, Jean (1998) Astronomical Algorithms (2nd Edition). Willmann-Bell,
Virginia. p. 63
"""
# based on redate.py by David Finlayson.
if JD < 0:
raise ValueError, "Julian Day must be positive"
dayofwk = int(math.fmod(int(JD + 1.5), 7))
(F, Z) = math.modf(JD + 0.5)
Z = int(Z)
if calendar in ["standard", "gregorian"]:
if JD < 2299160.5:
A = Z
else:
alpha = int((Z - 1867216.25) / 36524.25)
A = Z + 1 + alpha - int(alpha / 4)
elif calendar == "proleptic_gregorian":
alpha = int((Z - 1867216.25) / 36524.25)
A = Z + 1 + alpha - int(alpha / 4)
elif calendar == "julian":
A = Z
else:
raise ValueError, "unknown calendar, must be one of julian,standard,gregorian,proleptic_gregorian, got %s" % calendar
B = A + 1524
C = int((B - 122.1) / 365.25)
D = int(365.25 * C)
E = int((B - D) / 30.6001)
# Convert to date
day = B - D - int(30.6001 * E) + F
nday = B - D - 123
if nday <= 305:
dayofyr = nday + 60
else:
dayofyr = nday - 305
if E < 14:
month = E - 1
else:
month = E - 13
if month > 2:
year = C - 4716
else:
year = C - 4715
# a leap year?
leap = 0
if year % 4 == 0:
leap = 1
if calendar == "proleptic_gregorian" or (calendar in ["standard", "gregorian"] and JD >= 2299160.5):
if year % 100 == 0 and year % 400 != 0:
print year % 100, year % 400
leap = 0
if leap and month > 2:
dayofyr = dayofyr + leap
# Convert fractions of a day to time
(dfrac, days) = math.modf(day / 1.0)
(hfrac, hours) = math.modf(dfrac * 24.0)
(mfrac, minutes) = math.modf(hfrac * 60.0)
seconds = round(mfrac * 60.0) # seconds are rounded
if seconds > 59:
seconds = 0
minutes = minutes + 1
if minutes > 59:
minutes = 0
hours = hours + 1
if hours > 23:
hours = 0
days = days + 1
# return a 'real' datetime instance if calendar is gregorian.
if calendar == "proleptic_gregorian" or (calendar in ["standard", "gregorian"] and JD >= 2299160.5):
return real_datetime(year, month, int(days), int(hours), int(minutes), int(seconds))
else:
# or else, return a 'datetime-like' instance.
return datetime(year, month, int(days), int(hours), int(minutes), int(seconds), dayofwk, dayofyr)
def strptime(date_string, fmt):
"""A strptime(date string, format) that support dates before 1900."""
return real_datetime(*(time.strptime(date_string, fmt)[:6]))
