glibmm: Glib::Date Class Reference

glibmm 2.80.0

Public Types | Public Member Functions | Static Public Member Functions | Static Public Attributes | Related Symbols | List of all members
Glib::Date Class Reference

Julian calendar date. More...

`#include <glibmm/date.h>`

## Public Types
enum class | Month { Month::BAD_MONTH , Month::JANUARY , Month::FEBRUARY , Month::MARCH , Month::APRIL , Month::MAY , Month::JUNE , Month::JULY , Month::AUGUST , Month::SEPTEMBER , Month::OCTOBER , Month::NOVEMBER , Month::DECEMBER }
| Enumeration representing a month; values are Glib::Date::JANUARY, Glib::Date::FEBRUARY, etc. More...
enum class | Weekday { Weekday::BAD_WEEKDAY , Weekday::MONDAY , Weekday::TUESDAY , Weekday::WEDNESDAY , Weekday::THURSDAY , Weekday::FRIDAY , Weekday::SATURDAY , Weekday::SUNDAY }
| Enumeration representing a day of the week; Glib::Date::MONDAY, Glib::Date::TUESDAY, etc. More...
enum class | DMY { DMY::DAY , DMY::MONTH , DMY::YEAR }
| This enumeration isn't used in the API, but may be useful if you need to mark a number as a day, month, or year. More...
using | Day = guint8
using | Year = guint16

## Public Member Functions
| Date ()
| Construct an undefined date.
| Date (Day day, Month month, Year year)
| Construct a date with the given day, month and year.
| Date (guint32 julian_day)
| Construct a date from a julian day.
| Date (const GDate &castitem)
| Construct a Glib::Date by copying the contents of a GDate.
| Date (const Date &other)
| Construct a Glib::Date from another.
Date & | operator= (const Date &other)
| Assign another date to this one.
GDate * | gobj ()
| Provides access to the underlying C instance.
const GDate * | gobj () const
| Provides access to the underlying C instance.
void | clear ()
| Clear the date.
void | set_parse (const Glib::ustring & str)
| Parses a user-inputted string str, and try to figure out what date it represents, taking the current locale into account.
void | set_time (std::time_t timet)
| Sets the value of a date from a <type>std::time_t</type> value.
void | set_time_current ()
| Set this Glib::Date to the current time.
void | set_month (Month month)
| Sets the month of the year.
void | set_day (Day day)
| Sets the day of the month.
void | set_year (Year year)
| Sets the year.
void | set_dmy (Day day, Month month, Year year)
| Sets the value of a day, month, and year.
void | set_julian (guint32 julian_day)
| Sets the value of a GDate from a Julian day number.
Date & | add_days (int n_days)
| Add a number of days to a Date.
Date & | subtract_days (int n_days)
| Subtract n_days to a Date.
Date & | add_months (int n_months)
| Add n_months to a Date.
Date & | subtract_months (int n_months)
| Subtract n_months to a Date.
Date & | add_years (int n_years)
| Add n_days to a Date.
Date & | subtract_years (int n_years)
| Subtract n_years to a Date.
int | days_between (const Date &rhs) const
| Calculate days between two dates.
int | compare (const Date &rhs) const
| Compare two dates.
Date & | clamp (const Date &min_date, const Date &max_date)
| If date is prior to min_date, sets date equal to min_date.
Date & | clamp_min (const Date &min_date)
| If date is prior to min_date, sets date equal to min_date.
Date & | clamp_max (const Date &max_date)
| If date falls after max_date, sets date equal to max_date.
void | order (Date &other)
| Checks if date is less than or equal to other date, and swap the values if this is not the case.
Weekday | get_weekday () const
| Returns the day of the week for a Date.
int | get_weekday_as_int () const
| Returns the day of the week for a Date.
Month | get_month () const
| Returns the month of the year.
int | get_month_as_int () const
| Returns the month of the year.
Year | get_year () const
| Returns the year of a Date.
Day | get_day () const
| Returns the day of the month.
guint32 | get_julian () const
| Returns the Julian day or "serial number" of the Date.
unsigned int | get_day_of_year () const
| Returns the day of the year, where Jan 1 is the first day of the year.
unsigned int | get_monday_week_of_year () const
| Returns the week of the year, where weeks are understood to start on Monday.
unsigned int | get_sunday_week_of_year () const
| Returns the week of the year during which this date falls, if weeks are understood to being on Sunday.
unsigned int | get_iso8601_week_of_year () const
| Returns the week of the year, where weeks are interpreted according to ISO 8601.
bool | is_first_of_month () const
| Returns true if the date is on the first of a month.
bool | is_last_of_month () const
| Returns true if the date is the last day of the month.
Glib::ustring | format_string (const Glib::ustring & format) const
| Convert date to string.
void | to_struct_tm (struct tm &dest) const
| Fills in the date-related bits of a struct tm using the date value.
bool | valid () const
| Returns true if the Date represents an existing day.

## Static Public Member Functions
static guint8 | get_days_in_month (Month month, Year year)
| Returns the number of days in a month, taking leap years into account.
static guint8 | get_monday_weeks_in_year (Year year)
| Returns the number of weeks in the year, where weeks are taken to start on Monday.
static guint8 | get_sunday_weeks_in_year (Year year)
| Returns the number of weeks in the year, where weeks are taken to start on Sunday.
static bool | is_leap_year (Year year)
| Returns true if the year is a leap year.
static bool | valid_day (Day day)
| Returns true if the day of the month is valid (a day is valid if it's between 1 and 31 inclusive).
static bool | valid_month (Month month)
| Returns true if the month value is valid.
static bool | valid_year (Year year)
| Returns true if the year is valid.
static bool | valid_weekday (Weekday weekday)
| Returns true if the weekday is valid.
static bool | valid_julian (guint32 julian_day)
| Returns true if the Julian day is valid.
static bool | valid_dmy (Day day, Month month, Year year)
| Returns true if the day-month-year triplet forms a valid, existing day in the range of days Date understands (Year 1 or later, no more than a few thousand years in the future).

## Static Public Attributes
static const Day | BAD_DAY = 0
static const Year | BAD_YEAR = 0
static const guint32 | BAD_JULIAN = 0

## Related Symbols
(Note that these are not member symbols.)
bool | operator== (const Date &lhs, const Date &rhs)
bool | operator!= (const Date &lhs, const Date &rhs)
bool | operator< (const Date &lhs, const Date &rhs)
bool | operator> (const Date &lhs, const Date &rhs)
bool | operator<= (const Date &lhs, const Date &rhs)
bool | operator>= (const Date &lhs, const Date &rhs)

## Detailed Description

Julian calendar date.

## Member Typedef Documentation

## ◆ Day

using Glib::Date::Day = guint8

## ◆ Year

using Glib::Date::Year = guint16

## Constructor & Destructor Documentation

## ◆ Date() [1/5]

Glib::Date::Date | ( |  | ) |

Construct an undefined date.

## ◆ Date() [2/5]

Glib::Date::Date | ( | Day | day,
|  | Month | month,
|  | Year | year )

Construct a date with the given day, month and year.

Parameters

  day | The day.
  month | The month.
  year | The year.

## ◆ Date() [3/5]

Glib::Date::Date | ( | guint32 | julian_day | ) |
| explicit

Construct a date from a julian day.

Parameters

  julian_day | The julian day (guint32).

## ◆ Date() [4/5]

Glib::Date::Date | ( | const GDate & | castitem | ) |
| explicit

Construct a Glib::Date by copying the contents of a GDate.

Parameters

  castitem | The GDate.

Since glibmm 2.18

## ◆ Date() [5/5]

Glib::Date::Date | ( | const Date & | other | ) |

Construct a Glib::Date from another.

Parameters

  other | the other Glib::Date.

Since glibmm 2.18

## Member Function Documentation

## ◆ add_days()

Date & Glib::Date::add_days | ( | int | n_days | ) |

Add a number of days to a Date.

This method returns a reference to the object itself, so you can write code such as:

somedate.add_days(2).add_months(3).add_years(17);

Parameters

  n_days | Days to add.

Returns
  Resulting Date

## ◆ add_months()

Date & Glib::Date::add_months | ( | int | n_months | ) |

Add n_months to a Date.

This method returns a reference to the object itself, so you can write code such as:

somedate.add_years(2).add_months(3).add_days(17);

Parameters

  n_months | Months to add.

Returns
  Resulting Date

## ◆ add_years()

Date & Glib::Date::add_years | ( | int | n_years | ) |

Add n_days to a Date.

This method returns a reference to the object itself, so you can write code such as:

somedate.add_years(2).add_months(3).add_days(17);

Parameters

  n_years | Years to add.

Returns
  Resulting Date

## ◆ clamp()

Date & Glib::Date::clamp | ( | const Date & | min_date,
|  | const Date & | max_date )

If date is prior to min_date, sets date equal to min_date.

If date falls after max_date, sets date equal to max_date. All dates must be valid. See also clamp_min() and clamp_max(). This method returns a reference to the object itself.

Parameters

  min_date | Date minimum value.
  max_date | Date maximum value.

Returns
  Date in interval.

## ◆ clamp_max()

Date & Glib::Date::clamp_max | ( | const Date & | max_date | ) |

If date falls after max_date, sets date equal to max_date.

See also clamp(), and clamp_min(). This method returns a reference to the object itself.

Parameters

  max_date | Date maximum value.

Returns
  Date in interval.

## ◆ clamp_min()

Date & Glib::Date::clamp_min | ( | const Date & | min_date | ) |

If date is prior to min_date, sets date equal to min_date.

See also clamp(), and clamp_max(). This method returns a reference to the object itself.

Parameters

  min_date | Date minimum value.

Returns
  Date in interval.

## ◆ clear()

void Glib::Date::clear | ( |  | ) |

Clear the date.

The cleared dates will not represent an existing date, but will not contain garbage.

## ◆ compare()

int Glib::Date::compare | ( | const Date & | rhs | ) | const

Compare two dates.

Parameters

  rhs | Date to compare.

Returns
  Result of comparition.

## ◆ days_between()

int Glib::Date::days_between | ( | const Date & | rhs | ) | const

Calculate days between two dates.

Parameters

  rhs | Date.

Returns
  Numbers of days.

## ◆ format_string()

Glib::ustring Glib::Date::format_string | ( | const Glib::ustring & | format | ) | const

Convert date to string.

Parameters

  format | A format string as used by `strftime()`, in UTF-8 encoding. Only date formats are allowed, the result of time formats is undefined.

Returns
  The formatted date string.

Exceptions

  Glib::ConvertError |

## ◆ get_day()

Day Glib::Date::get_day | ( |  | ) | const

Returns the day of the month.

The date must be valid.

Returns
  Day of the month..

## ◆ get_day_of_year()

unsigned int Glib::Date::get_day_of_year | ( |  | ) | const

Returns the day of the year, where Jan 1 is the first day of the year.

The date must be valid.

Returns
  Julian day.

## ◆ get_days_in_month()

static guint8 Glib::Date::get_days_in_month | ( | Month | month,
|  | Year | year )
| static

Returns the number of days in a month, taking leap years into account.

Parameters

  month | Month.
  year | Year.

Returns
  Number of days in month during the year.

## ◆ get_iso8601_week_of_year()

unsigned int Glib::Date::get_iso8601_week_of_year | ( |  | ) | const

Returns the week of the year, where weeks are interpreted according to ISO 8601.

The date must be valid.

Returns
  ISO 8601 week number of the year.

Since glibmm 2.22

## ◆ get_julian()

guint32 Glib::Date::get_julian | ( |  | ) | const

Returns the Julian day or "serial number" of the Date.

The Julian day is simply the number of days since January 1, Year 1; i.e., January 1, Year 1 is Julian day 1; January 2, Year 1 is Julian day 2, etc. The date must be valid.

Returns
  Julian day.

## ◆ get_monday_week_of_year()

unsigned int Glib::Date::get_monday_week_of_year | ( |  | ) | const

Returns the week of the year, where weeks are understood to start on Monday.

If the date is before the first Monday of the year, return 0. The date must be valid.

Returns
  Week of the year.

## ◆ get_monday_weeks_in_year()

static guint8 Glib::Date::get_monday_weeks_in_year | ( | Year | year | ) |
| static

Returns the number of weeks in the year, where weeks are taken to start on Monday.

Will be 52 or 53. (Years always have 52 7-day periods, plus 1 or 2 extra days depending on whether it's a leap year. This function is basically telling you how many Mondays are in the year, i.e. there are 53 Mondays if one of the extra days happens to be a Monday.)

Parameters

  year | Year to count weeks in.

Returns
  Number of weeks.

## ◆ get_month()

Month Glib::Date::get_month | ( |  | ) | const

Returns the month of the year.

The date must be valid.

Returns
  Month of the year as a Date::Month.

## ◆ get_month_as_int()

int Glib::Date::get_month_as_int | ( |  | ) | const

Returns the month of the year.

The date must be valid.

Returns
  Month of the year as an int. January=1 .. December=12.

## ◆ get_sunday_week_of_year()

unsigned int Glib::Date::get_sunday_week_of_year | ( |  | ) | const

Returns the week of the year during which this date falls, if weeks are understood to being on Sunday.

Can return 0 if the day is before the first Sunday of the year. The date must be valid.

Returns
  Week of the year.

## ◆ get_sunday_weeks_in_year()

static guint8 Glib::Date::get_sunday_weeks_in_year | ( | Year | year | ) |
| static

Returns the number of weeks in the year, where weeks are taken to start on Sunday.

Will be 52 or 53. (Years always have 52 7-day periods, plus 1 or 2 extra days depending on whether it's a leap year. This function is basically telling you how many Sundays are in the year, i.e. there are 53 Sundays if one of the extra days happens to be a Sunday.)

Parameters

  year | Year to count weeks in.

Returns
  Number of weeks.

## ◆ get_weekday()

Weekday Glib::Date::get_weekday | ( |  | ) | const

Returns the day of the week for a Date.

The date must be valid.

Returns
  Day of the week as a Date::Weekday.

## ◆ get_weekday_as_int()

int Glib::Date::get_weekday_as_int | ( |  | ) | const

Returns the day of the week for a Date.

The date must be valid.

Returns
  Day of the week as an int. Monday=1 .. Sunday=7.

## ◆ get_year()

Year Glib::Date::get_year | ( |  | ) | const

Returns the year of a Date.

The date must be valid.

Returns
  Year in which the date falls.

## ◆ gobj() [1/2]

GDate * Glib::Date::gobj | ( |  | ) |
| inline

Provides access to the underlying C instance.

## ◆ gobj() [2/2]

const GDate * Glib::Date::gobj | ( |  | ) | const
| inline

Provides access to the underlying C instance.

## ◆ is_first_of_month()

bool Glib::Date::is_first_of_month | ( |  | ) | const

Returns true if the date is on the first of a month.

The date must be valid.

Returns
  true if the date is the first of the month.

## ◆ is_last_of_month()

bool Glib::Date::is_last_of_month | ( |  | ) | const

Returns true if the date is the last day of the month.

The date must be valid.

Returns
  true if the date is the last day of the month.

## ◆ is_leap_year()

static bool Glib::Date::is_leap_year | ( | Year | year | ) |
| static

Returns true if the year is a leap year.

Parameters

  year | Year to check.

Returns
  true if the year is a leap year.

## ◆ operator=()

Date & Glib::Date::operator= | ( | const Date & | other | ) |

Assign another date to this one.

For example:

...
Glib::Date my_date;
my_date = other_date;

Parameters

  other | The other Glib::Date.

Since glibmm 2.18

## ◆ order()

void Glib::Date::order | ( | Date & | other | ) |

Checks if date is less than or equal to other date, and swap the values if this is not the case.

Parameters

  other | Date ro compare.

Returns
  Date.

## ◆ set_day()

void Glib::Date::set_day | ( | Day | day | ) |

Sets the day of the month.

If the resulting day-month-year triplet is invalid, the date will be invalid.

Parameters

  day | Day to set.

## ◆ set_dmy()

void Glib::Date::set_dmy | ( | Day | day,
|  | Month | month,
|  | Year | year )

Sets the value of a day, month, and year.

. If the resulting day-month-year triplet is invalid, the date will be invalid.

Parameters

  day | Day to set.
  month | Month to set.
  year | Year to set.

## ◆ set_julian()

void Glib::Date::set_julian | ( | guint32 | julian_day | ) |

Sets the value of a GDate from a Julian day number.

Parameters

  julian_day | Julian day to set.

## ◆ set_month()

void Glib::Date::set_month | ( | Month | month | ) |

Sets the month of the year.

If the resulting day-month-year triplet is invalid, the date will be invalid.

Parameters

  month | Month to set.

## ◆ set_parse()

void Glib::Date::set_parse | ( | const Glib::ustring & | str | ) |

Parses a user-inputted string str, and try to figure out what date it represents, taking the current locale into account.

If the string is successfully parsed, the date will be valid after the call. Otherwise, it will be invalid. This function is not appropriate for file formats and the like; it isn't very precise, and its exact behavior varies with the locale. It's intended to be a heuristic routine that guesses what the user means by a given string (and it does work pretty well in that capacity).

Parameters

  str | String to parse.

## ◆ set_time()

void Glib::Date::set_time | ( | std::time_t | timet | ) |

Sets the value of a date from a <type>std::time_t</type> value.

Parameters

  timet | std::time_t value to set

See also
  set_time_current()

Since: 2.10

## ◆ set_time_current()

void Glib::Date::set_time_current | ( |  | ) |

Set this Glib::Date to the current time.

## ◆ set_year()

void Glib::Date::set_year | ( | Year | year | ) |

Sets the year.

If the resulting day-month-year triplet is invalid, the date will be invalid.

Parameters

  year | Year to set.

## ◆ subtract_days()

Date & Glib::Date::subtract_days | ( | int | n_days | ) |

Subtract n_days to a Date.

This method returns a reference to the object itself, so you can write code such as:

somedate.subtract_days(2).subtract_months(3).subtract_years(17);

Parameters

  n_days | Days to subtract.

Returns
  Resulting Date

## ◆ subtract_months()

Date & Glib::Date::subtract_months | ( | int | n_months | ) |

Subtract n_months to a Date.

This method returns a reference to the object itself, so you can write code such as:

somedate.subtract_years(2).subtract_months(3).subtract_days(17);

Parameters

  n_months | Months to subtract.

Returns
  Resulting Date

## ◆ subtract_years()

Date & Glib::Date::subtract_years | ( | int | n_years | ) |

Subtract n_years to a Date.

This method returns a reference to the object itself, so you can write code such as:

somedate.subtract_years(2).subtract_months(3).subtract_days(17);

Parameters

  n_years | Years to subtract.

Returns
  Resulting Date

## ◆ to_struct_tm()

void Glib::Date::to_struct_tm | ( | struct tm & | dest | ) | const

Fills in the date-related bits of a struct tm using the date value.

Initializes the non-date parts with something sane but meaningless.

Parameters

  dest | Struct tm to fill.

## ◆ valid()

bool Glib::Date::valid | ( |  | ) | const

Returns true if the Date represents an existing day.

Returns
  true if the date is valid.

## ◆ valid_day()

static bool Glib::Date::valid_day | ( | Day | day | ) |
| static

Returns true if the day of the month is valid (a day is valid if it's between 1 and 31 inclusive).

Parameters

  day | Day to check.

Returns
  true if the day is valid.

## ◆ valid_dmy()

static bool Glib::Date::valid_dmy | ( | Day | day,
|  | Month | month,
|  | Year | year )
| static

Returns true if the day-month-year triplet forms a valid, existing day in the range of days Date understands (Year 1 or later, no more than a few thousand years in the future).

Parameters

  day | Day to check.
  month | Month to check.
  year | Year to check.

Returns
  true if the date is a valid one.

## ◆ valid_julian()

static bool Glib::Date::valid_julian | ( | guint32 | julian_day | ) |
| static

Returns true if the Julian day is valid.

Anything greater than zero is basically a valid Julian, though there is a 32-bit limit.

Parameters

  julian_day | Julian day to check.

Returns
  true if the Julian day is valid.

## ◆ valid_month()

static bool Glib::Date::valid_month | ( | Month | month | ) |
| static

Returns true if the month value is valid.

The 12 Date::Month enumeration values are the only valid months.

Parameters

  month | Month to check.

Returns
  true if the month is valid.

## ◆ valid_weekday()

static bool Glib::Date::valid_weekday | ( | Weekday | weekday | ) |
| static

Returns true if the weekday is valid.

The 7 Date::Weekday enumeration values are the only valid.

Parameters

  weekday | Weekday to check.

Returns
  true if the weekday is valid.

## ◆ valid_year()

static bool Glib::Date::valid_year | ( | Year | year | ) |
| static

Returns true if the year is valid.

Any year greater than 0 is valid, though there is a 16-bit limit to what Date will understand.

Parameters

  year | Year to check.

Returns
  true if the year is valid.

## Friends And Related Symbol Documentation

## ◆ operator!=()

bool operator!= | ( | const Date & | lhs,
|  | const Date & | rhs )
| related

## ◆ operator<()

bool operator< | ( | const Date & | lhs,
|  | const Date & | rhs )
| related

## ◆ operator<=()

bool operator<= | ( | const Date & | lhs,
|  | const Date & | rhs )
| related

## ◆ operator==()

bool operator== | ( | const Date & | lhs,
|  | const Date & | rhs )
| related

## ◆ operator>()

bool operator> | ( | const Date & | lhs,
|  | const Date & | rhs )
| related

## ◆ operator>=()

bool operator>= | ( | const Date & | lhs,
|  | const Date & | rhs )
| related

## Member Data Documentation

## ◆ BAD_DAY

const Day Glib::Date::BAD_DAY = 0
| static

## ◆ BAD_JULIAN

const guint32 Glib::Date::BAD_JULIAN = 0
| static

## ◆ BAD_YEAR

const Year Glib::Date::BAD_YEAR = 0
| static