dates module¶

The dates module implements classes for representing and manipulating several date types.

Contents¶

BaseDate
CalendarDateMixin
JulianDay
GregorianDate
HebrewDate

Notes

All instances of the classes in this module should be treated as read only. No attributes should be changed once they’re created.

class pyluach.dates.BaseDate[source]¶

Bases: object

BaseDate is a base class for all date types.

It provides the following arithmetic and comparison operators common to all child date types.

Operation	Result
d2 = date1 + int	New date `int` days after date1
d2 = date1 - int	New date `int` days before date1
int = date1 - date2	Integer equal to the absolute value of the difference between date1 and date2
date1 > date2	True if date1 occurs later than date2
date1 < date2	True if date1 occurs earlier than date2
date1 == date2	True if date1 occurs on the same day as date2
date1 != date2	True if `date1 == date2` is False
date1 >=, <= date2	True if both are True

Any child of BaseDate that implements a jd attribute representing the Julian Day of that date can be compared to and diffed with any other valid date type.

isoweekday()[source]¶

Return the day of the week corresponding to the iso standard.

Returns: An integer representing the day of the week where Monday is 1 and and Sunday is 7.
Return type: int

shabbos()[source]¶

Return the Shabbos on or following the date.

Returns: Self if it’s Shabbos or else the following Shabbos as the same date type as operated on.
Return type: Date

class pyluach.dates.CalendarDateMixin(year, month, day, jd=None)[source]¶

Bases: object

CalendarDateMixin is a mixin for Hebrew and Gregorian dates.

Parameters

Year (int) –
Month (int) –
day (int) –

year¶

Type: int

month¶

Type: int

day¶

Type: int

jd¶

The equivelant Julian day at midnight.

Type: float

dict()[source]¶

Return the date as a dictionary.

Returns: A dictionary in the form {'year': int, 'month': int, 'day': int}.
Return type: Dict

tuple()[source]¶

Return date as tuple.

Returns: A tuple of ints in the form (year, month, day).
Return type: tuple of ints

weekday()[source]¶

Return day of week as an integer.

Returns: An integer representing the day of the week with Sunday as 1 through Saturday as 7.
Return type: int

class pyluach.dates.GregorianDate(year, month, day, jd=None)[source]¶

Bases: pyluach.dates.BaseDate, pyluach.dates.CalendarDateMixin

A GregorianDate object represents a Gregorian date (year, month, day).

This is an idealized date with the current Gregorian calendar infinitely extended in both directions.

Parameters

year (int) –
month (int) –
day (int) –
jd (float, optional) – This parameter should not be assigned manually.

year¶

Type: int

month¶

Type: int

day¶

Type: int

jd¶

The corresponding Julian Day Number at midnight (as n.5).

Type: float(property)

Warning

Although B.C.E. dates are allowed, they should be treated as approximations as they may return inconsistent results when converting between date types and using arithmetic and comparison operators!

dict()¶

Return the date as a dictionary.

Returns: A dictionary in the form {'year': int, 'month': int, 'day': int}.
Return type: Dict

static from_pydate(pydate)[source]¶

Return a GregorianDate instance from a python date object.

Parameters: pydate (datetime.date) – A python standard library datetime.date instance.
Returns
Return type: GregorianDate

is_leap()[source]¶

Return if the date is in a leap year

Returns: True if the date is in a leap year, False otherwise.
Return type: bool

isoweekday()¶

Return the day of the week corresponding to the iso standard.

Returns: An integer representing the day of the week where Monday is 1 and and Sunday is 7.
Return type: int

property jd¶

Return the corresponding Julian day number.

This property retrieves the corresponding Julian Day as a float if it was passed into the init method or already calculated, and if it wasn’t, it calculates it and saves it for later retrievals and returns it.

Returns: The Julian day number at midnight.
Return type: float

shabbos()¶

Return the Shabbos on or following the date.

Returns: Self if it’s Shabbos or else the following Shabbos as the same date type as operated on.
Return type: Date

to_heb()[source]¶

Convert to Hebrew date.

Returns: The equivalent HebrewDate instance.
Return type: HebrewDate

to_jd()[source]¶

Convert to a Julian day.

Returns: The equivalent JulianDay instance.
Return type: JulianDay

to_pydate()[source]¶

Convert to a standard library date.

Returns: The equivalent datetime.date instance.
Return type: datetime.date

static today()[source]¶

Return a GregorianDate instance for the current day.

This static method wraps the Python standard library’s date.today() method to get the date from the timestamp.

Returns: The current Gregorian date from the computer’s timestamp.
Return type: GregorianDate

tuple()¶

Return date as tuple.

Returns: A tuple of ints in the form (year, month, day).
Return type: tuple of ints

weekday()¶

Return day of week as an integer.

Returns: An integer representing the day of the week with Sunday as 1 through Saturday as 7.
Return type: int

class pyluach.dates.HebrewDate(year, month, day, jd=None)[source]¶

Bases: pyluach.dates.BaseDate, pyluach.dates.CalendarDateMixin

A class for manipulating Hebrew dates.

Parameters

year (int) – The Hebrew year. If the year is less than 1 it will raise a ValueError.
month (int) – The Hebrew month starting with Nissan as 1 (and Tishrei as 7). If there is a second Adar in the year it is represented as 13. A month below 1 or above the last month will raise a ValueError.
day (int) – The Hebrew day of the month. An invalid day will raise a ValueError.
jd (float, optional) – This parameter should not be assigned manually.

year¶

Type: int

month¶

The Hebrew month starting with Nissan as 1 (and Tishrei as 7). If there is a second Adar it is represented as 13.

Type: int

day¶

The day of the month.

Type: int

dict()¶

Return the date as a dictionary.

Returns: A dictionary in the form {'year': int, 'month': int, 'day': int}.
Return type: Dict

static from_pydate(pydate)[source]¶

Return a HebrewDate from a python date object.

Parameters: pydate (datetime.date) – A python standard library datetime.date instance
Returns
Return type: HebrewDate

isoweekday()¶

Return the day of the week corresponding to the iso standard.

Returns: An integer representing the day of the week where Monday is 1 and and Sunday is 7.
Return type: int

property jd¶

Return the corresponding Julian day number.

This property retrieves the corresponding Julian Day as a float if it was passed into the init method or already calculated, and if it wasn’t, it calculates it, saves it for later retrievals, and returns it.

Returns: The Julian day number at midnight.
Return type: float

shabbos()¶

Return the Shabbos on or following the date.

Returns: Self if it’s Shabbos or else the following Shabbos as the same date type as operated on.
Return type: Date

to_greg()[source]¶

Convert to a Gregorian date.

Returns: The equivalent GregorianDate instance.
Return type: GregorianDate

to_jd()[source]¶

Convert to a Julian day.

Returns: The equivalent JulianDay instance.
Return type: JulianDay

to_pydate()[source]¶

Convert to a standard library date.

Returns: The equivalent datetime.date instance.
Return type: datetime.date

static today()[source]¶

Return HebrewDate instance for the current day.

This static method wraps the Python standard library’s date.today() method to get the date from the timestamp.

Returns: The current Hebrew date from the computer’s timestamp.
Return type: HebrewDate

Notes

This method coverts the Gregorian date from the time stamp to a Hebrew date, so if it is after nightfall but before midnight you will have to add one day, ie. today = HebrewDate.today() + 1.

tuple()¶

Return date as tuple.

Returns: A tuple of ints in the form (year, month, day).
Return type: tuple of ints

weekday()¶

Return day of week as an integer.

Returns: An integer representing the day of the week with Sunday as 1 through Saturday as 7.
Return type: int

class pyluach.dates.JulianDay(day)[source]¶

Bases: pyluach.dates.BaseDate

A JulianDay object represents a Julian Day at midnight.

Parameters: day (float or int) – The julian day. Note that Julian days start at noon so day number 10 is represented as 9.5 which is day 10 at midnight.

day¶

The Julian Day Number at midnight (as n.5)

Type: float

jd¶

Alias for day.

Type: float

static from_pydate(pydate)[source]¶

Return a JulianDay from a python date object.

Parameters: pydate (datetime.date) – A python standard library datetime.date instance
Returns
Return type: JulianDay

isoweekday()¶

Return the day of the week corresponding to the iso standard.

Returns: An integer representing the day of the week where Monday is 1 and and Sunday is 7.
Return type: int

shabbos()¶

Return the Shabbos on or following the date.

Returns: Self if it’s Shabbos or else the following Shabbos as the same date type as operated on.
Return type: Date

to_greg()[source]¶

Convert JulianDay to a Gregorian Date.

Returns: The equivalent Gregorian date instance.
Return type: GregorianDate

Notes

This method uses the Fliegel-Van Flandern algorithm.

to_heb()[source]¶

Convert to a Hebrew date.

Returns: The equivalent Hebrew date instance.
Return type: HebrewDate

to_pydate()[source]¶

Convert to a datetime.date object.

Returns: A standard library datetime.date instance.
Return type: datetime.date

static today()[source]¶

Return instance of current Julian day from timestamp.

Extends the built-in datetime.date.today().

Returns: A JulianDay instance representing the current Julian day from the timestamp.
Return type: JulianDay

weekday()[source]¶

Return weekday of date.

Returns: The weekday with Sunday as 1 through Saturday as 7.
Return type: int