supernovas::Calendar Class Reference

Type of calendar used for representing dates, such as Gregorian, Roman, or astronomical. More...

#include <supernovas.h>

Inheritance diagram for supernovas::Calendar:

Public Member Functions
CalendarDate	date (const struct timespec *ts) const
	Returns a new calendar date instance, in this calendar, for the given astronomical time specification.
CalendarDate	date (double jd) const
	Returns a new calendar date instance, in this calendar, for the specified Julian date.
CalendarDate	date (int year, int month, int day, const TimeAngle &time=TimeAngle::zero()) const
	Returns a new calendar date instance for the date and time specified in this calendar.
CalendarDate	date (time_t t, long nanos=0) const
	Returns a new calendar date instance, in this calendar, for the specified UNIX time.
CalendarDate	parse_date (const std::string &str, enum novas_date_format fmt=NOVAS_YMD) const
	Returns a new calendar date instance, in this calendar, for the specified string date / time representation, if possible, or else std::nullopt.
std::string	to_string () const
	Returns a string representation of this type of calendar.
enum novas_calendar_type	type () const
	Returns the type of this calendar, that is whether it is a Gregorian, Roman / Julian, or astronomical calendar.
Public Member Functions inherited from supernovas::Validating
bool	is_valid () const
	Returns the previously set 'valid' stae of the implementing instance.
	operator bool () const
	Objects that implement Validating can be used in conditionals directly, without explicitly calling is_valid().

Static Public Member Functions
static Calendar	astronomical ()
	Returns a new astronomical calendar instance.
static Calendar	gregorian ()
	Returns a new Gregorian calendar instance.
static Calendar	roman ()
	Returns a new Roman / Julian calendar instance.

Additional Inherited Members
Protected Member Functions inherited from supernovas::Validating
	Validating ()
	dummy constructor;
Protected Attributes inherited from supernovas::Validating
bool	_valid = false
	the state variable.

Detailed Description

Type of calendar used for representing dates, such as Gregorian, Roman, or astronomical.

Member Function Documentation

astronomical()

Calendar supernovas::Calendar::astronomical ( )

static

Returns a new astronomical calendar instance.

The astronomical calendat is the conventional calendar of date, that is the Roman / Julian calendar prior to the Gregorian calendar reform of 1582; and the Gregorian calendar after the date of the reform.

Returns

an astronomical calendar / conventional calendar of date instance.

See also

Calendar::roman()

Calendar::gregorian()

References NOVAS_ASTRONOMICAL_CALENDAR.

Referenced by supernovas::Time::operator-(), and supernovas::Time::to_calendar_date().

date() [1/4]

CalendarDate supernovas::Calendar::date

(

const struct timespec *

ts

)

const

Returns a new calendar date instance, in this calendar, for the given astronomical time specification.

Parameters

ts	Pointer to the astronomical time specification

Returns

a new calendar date, in this calendar, corresponding to the specified astronomical time.

See also

date(), parse_date()

References date().

date() [2/4]

CalendarDate supernovas::Calendar::date

(

double

jd

)

const

Returns a new calendar date instance, in this calendar, for the specified Julian date.

Parameters

jd	[day] Julian Day

Returns

a new calendar date, in this calendar, corresponding to the specified Julian date.

See also

CalendarDate::CalendarDate(), date(), parse_date()

References supernovas::Validating::is_valid().

date() [3/4]

CalendarDate supernovas::Calendar::date	(	int	year,
		int	month,
		int	day,
		const TimeAngle &	time = TimeAngle::zero() ) const

Returns a new calendar date instance for the date and time specified in this calendar.

Parameters

year	[yr] calendar year
month	[month] calendar month [1:12]
day	[day] calendar day-of-month [1:31]
Time of observation and astronomical timescales	time of day

Returns

a date instance for the specified date in this calendar.

See also

CalendarDate::CalendarDate(), date(), parse_date()

References supernovas::Validating::is_valid().

Referenced by date(), parse_date(), and supernovas::Time::to_calendar_date().

date() [4/4]

CalendarDate supernovas::Calendar::date	(	time_t	t,
		long	nanos = 0 ) const

Returns a new calendar date instance, in this calendar, for the specified UNIX time.

Parameters

t	[s] UNIX time (seconds since the Gregorian date of January 1, 1970).
nanos	[ns] sub-second time component

Returns

a new calendar date, in this calendar, corresponding to the specified UNIX time.

See also

date(), date(double)

References supernovas::Unit::day, NOVAS_JD_J2000, supernovas::Unit::ns, and UNIX_UTC_J2000.

gregorian()

Calendar supernovas::Calendar::gregorian ( )

static

Returns a new Gregorian calendar instance.

Returns

a Gregorian calendar instance

See also

roman(), astronomical()

References NOVAS_GREGORIAN_CALENDAR.

parse_date()

CalendarDate supernovas::Calendar::parse_date	(	const std::string &	str,
		enum novas_date_format	fmt = NOVAS_YMD ) const

Returns a new calendar date instance, in this calendar, for the specified string date / time representation, if possible, or else std::nullopt.

Parameters

str	The string date / time specification. There is a lot of flexibility on what dates/times may be parsed. See novas_parse_date_format() for details.
fmt	The date representation, such as NOVAS_YMD, NOVAS_DMY, or NOVAS_MDY, specifying the order in which the year (Y), month (M), and day (D) components are expected in the input string representation.

Returns

A new calendar date, in this calendar, or else CalendarDate::undefined() if the string date could not be parsed.

See also

CalendarDate::to_string(), date()

novas_parse_date(), novas_parse_ido_date(), novas_parse_date_format() for more managed parsing from strings.

References date(), novas_parse_date_format(), and supernovas::CalendarDate::undefined().

roman()

Calendar supernovas::Calendar::roman ( )

static

Returns a new Roman / Julian calendar instance.

Returns

a Roman / Julian calendar instance

See also

gregorian(), astronomical()

References NOVAS_ROMAN_CALENDAR.

to_string()

std::string supernovas::Calendar::to_string

(

)

const

Returns a string representation of this type of calendar.

Returns

A string representation of the calendar, such as "Gregorian calendar".

References NOVAS_GREGORIAN_CALENDAR, and NOVAS_ROMAN_CALENDAR.

type()

enum novas_calendar_type supernovas::Calendar::type

(

)

const

Returns the type of this calendar, that is whether it is a Gregorian, Roman / Julian, or astronomical calendar.

The astronomical calendat is the conventional calendar of date.

Returns

The type of calendar, e.g. NOVAS_GREGORIAN_CALENDAR, NOVAS_ROMAN_CALENDAR, or NOVAS_ASTRONOMICAL calendar.