Libical API Documentation 3.0

Data Structures | Macros | Typedefs | Functions
icaltime.h File Reference

struct icaltimetype is a pseudo-object that abstracts time handling. More...

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## Data Structures
struct | icaltime_span
struct | icaltimetype

## Typedefs
typedef struct icaltime_span | icaltime_span
typedef struct icaltimetype | icaltimetype
typedef struct _icaltimezone | icaltimezone

## Functions
void | icaltime_adjust (struct icaltimetype *tt, const int days, const int hours, const int minutes, const int seconds)
| Internal, shouldn't be part of the public API. More...
const char * | icaltime_as_ical_string (const struct icaltimetype tt)
| Returns a string represention of the time, in RFC5545 format. More...
char * | icaltime_as_ical_string_r (const struct icaltimetype tt)
| Returns a string represention of the time, in RFC5545 format. More...
time_t | icaltime_as_timet (const struct icaltimetype)
time_t | icaltime_as_timet_with_zone (const struct icaltimetype tt, const icaltimezone *zone)
| Returns the time as seconds past the UNIX epoch, using the given timezone. More...
int | icaltime_compare (const struct icaltimetype a, const struct icaltimetype b)
| Returns -1, 0, or 1 to indicate that a is less than b, a equals b, or a is greater than b. More...
int | icaltime_compare_date_only (const struct icaltimetype a, const struct icaltimetype b)
| Like icaltime_compare, but only use the date parts. More...
int | icaltime_compare_date_only_tz (const struct icaltimetype a, const struct icaltimetype b, icaltimezone *tz)
| Like icaltime_compare, but only use the date parts; accepts timezone. More...
struct icaltimetype | icaltime_convert_to_zone (const struct icaltimetype tt, icaltimezone *zone)
| Converts time to a given timezone. More...
struct icaltimetype | icaltime_current_time_with_zone (const icaltimezone *zone)
| Convenience constructor. More...
int | icaltime_day_of_week (const struct icaltimetype t)
| Returns the day of the week of the given time. More...
int | icaltime_day_of_year (const struct icaltimetype t)
| Returns the day of the year, counting from 1 (Jan 1st).
int | icaltime_days_in_month (const int month, const int year)
int | icaltime_days_in_year (const int year)
struct icaltimetype | icaltime_from_day_of_year (const int doy, const int year)
| Contructor. More...
struct icaltimetype | icaltime_from_string (const char *str)
| Contructor. More...
struct icaltimetype | icaltime_from_timet_with_zone (const time_t tm, const int is_date, const icaltimezone *zone)
| Constructor. More...
const icaltimezone * | icaltime_get_timezone (const struct icaltimetype t)
| Returns the timezone.
const char * | icaltime_get_tzid (const struct icaltimetype t)
| Returns the tzid, or NULL for a floating time.
int | icaltime_is_date (const struct icaltimetype t)
| Returns true if time is a DATE. More...
int | icaltime_is_leap_year (const int year)
| Returns whether the specified year is a leap year. More...
int | icaltime_is_null_time (const struct icaltimetype t)
| Returns true if the time is null.
int | icaltime_is_utc (const struct icaltimetype t)
| Returns true if the time is relative to UTC zone. More...
int | icaltime_is_valid_time (const struct icaltimetype t)
| Returns false if the time is clearly invalid, but is not null. More...
struct icaltimetype | icaltime_normalize (const struct icaltimetype t)
| Normalizes the icaltime, so all of the time components are in their normal ranges. More...
struct icaltimetype | icaltime_null_date (void)
| Constructor. More...
struct icaltimetype | icaltime_null_time (void)
| Constructor. More...
struct icaltimetype | icaltime_set_timezone (struct icaltimetype *t, const icaltimezone *zone)
| Sets the timezone. More...
int | icaltime_span_contains (icaltime_span *s, icaltime_span *container)
| Returns true if the span is totally within the containing span. More...
struct icaltime_span | icaltime_span_new (struct icaltimetype dtstart, struct icaltimetype dtend, int is_busy)
| Builds an icaltimespan given a start time, end time and busy value. More...
int | icaltime_span_overlaps (icaltime_span *s1, icaltime_span *s2)
| Returns true if the two spans overlap. More...
int | icaltime_start_doy_week (const struct icaltimetype t, int fdow)
| Returns the day of the year for the first day of the week that the given time is within. More...
struct icaltimetype | icaltime_today (void)
| Convenience constructor. More...
int | icaltime_week_number (const struct icaltimetype t)
| Returns the week number for the week the given time is within. More...

## Detailed Description

struct icaltimetype is a pseudo-object that abstracts time handling.

It can represent either a DATE or a DATE-TIME (floating, UTC or in a given timezone), and it keeps track internally of its native timezone.

The typical usage is to call the correct constructor specifying the desired timezone. If this is not known until a later time, the correct behavior is to specify a NULL timezone and call icaltime_convert_to_zone() at a later time.

There are several ways to create a new icaltimetype:

- icaltime_null_time()
- icaltime_null_date()
- icaltime_current_time_with_zone()
- icaltime_today()
- icaltime_from_timet_with_zone(time_t tm, int is_date, icaltimezone *zone)
- icaltime_from_day_of_year(int doy, int year)

italtimetype objects can be converted to different formats:

- icaltime_as_timet(struct icaltimetype tt)
- icaltime_as_timet_with_zone(struct icaltimetype tt, icaltimezone *zone)
- icaltime_as_ical_string(struct icaltimetype tt)

Accessor methods include:

- icaltime_get_timezone(struct icaltimetype t)
- icaltime_get_tzid(struct icaltimetype t)
- icaltime_set_timezone(struct icaltimetype t, const icaltimezone *zone)
- icaltime_day_of_year(struct icaltimetype t)
- icaltime_day_of_week(struct icaltimetype t)
- icaltime_start_doy_week(struct icaltimetype t, int fdow)
- icaltime_week_number(struct icaltimetype t)

Query methods include:

- icaltime_is_null_time(struct icaltimetype t)
- icaltime_is_valid_time(struct icaltimetype t)
- icaltime_is_date(struct icaltimetype t)
- icaltime_is_utc(struct icaltimetype t)

Modify, compare and utility methods include:

- icaltime_compare(struct icaltimetype a,struct icaltimetype b)
- icaltime_compare_date_only(struct icaltimetype a, struct icaltimetype b)
- icaltime_adjust(struct icaltimetype *tt, int days, int hours, int minutes, int seconds);
- icaltime_normalize(struct icaltimetype t);
- icaltime_convert_to_zone(const struct icaltimetype tt, icaltimezone *zone);

## Function Documentation

## ◆ icaltime_adjust()

void icaltime_adjust | ( | struct icaltimetype * | tt,
|  | const int | days,
|  | const int | hours,
|  | const int | minutes,
|  | const int | seconds
| ) |  |

Internal, shouldn't be part of the public API.

Adds or subtracts a number of days, hours, minutes and seconds.

Adds or subtracts a time from a icaltimetype. This time is given as a number of days, hours, minutes and seconds.

Note
  This function is exactly the same as icaltimezone_adjust_change() except for the type of the first parameter.

## ◆ icaltime_as_ical_string()

const char * icaltime_as_ical_string | ( | const struct icaltimetype | tt | ) |

Returns a string represention of the time, in RFC5545 format.

Ownership
  The created string is owned by libical.

## ◆ icaltime_as_ical_string_r()

char * icaltime_as_ical_string_r | ( | const struct icaltimetype | tt | ) |

Returns a string represention of the time, in RFC5545 format.

Ownership
  The string is owned by the caller.

## ◆ icaltime_as_timet()

time_t icaltime_as_timet | ( | const struct icaltimetype | tt | ) |

Returns the time as seconds past the UNIX epoch.

This function probably won't do what you expect. In particular, you should only pass an icaltime in UTC, since no conversion is done. Even in that case, it's probably better to just use icaltime_as_timet_with_zone().

## ◆ icaltime_as_timet_with_zone()

time_t icaltime_as_timet_with_zone | ( | const struct icaltimetype | tt,
|  | const icaltimezone * | zone
| ) |  |

Returns the time as seconds past the UNIX epoch, using the given timezone.

This convenience method combines a call to icaltime_convert_to_zone() with a call to icaltime_as_timet(). If the input timezone is null, no conversion is done; that is, the time is simply returned as time_t in its native timezone.

## ◆ icaltime_compare()

int icaltime_compare | ( | const struct icaltimetype | a,
|  | const struct icaltimetype | b
| ) |  |

Returns -1, 0, or 1 to indicate that a is less than b, a equals b, or a is greater than b.

This converts both times to the UTC timezone and compares them.

## ◆ icaltime_compare_date_only()

int icaltime_compare_date_only | ( | const struct icaltimetype | a,
|  | const struct icaltimetype | b
| ) |  |

Like icaltime_compare, but only use the date parts.

This converts both times to the UTC timezone and compares their date components.

## ◆ icaltime_compare_date_only_tz()

int icaltime_compare_date_only_tz | ( | const struct icaltimetype | a,
|  | const struct icaltimetype | b,
|  | icaltimezone * | tz
| ) |  |

Like icaltime_compare, but only use the date parts; accepts timezone.

This converts both times to the given timezone and compares their date components.

## ◆ icaltime_convert_to_zone()

struct icaltimetype icaltime_convert_to_zone | ( | const struct icaltimetype | tt,
|  | icaltimezone * | zone
| ) |  |

Converts time to a given timezone.

Converts a time from its native timezone to a given timezone.

If tt is a date, the returned time is an exact copy of the input. If it's a floating time, the returned object represents the same time translated to the given timezone. Otherwise the time will be converted to the new time zone, and its native timezone set to the right timezone.

## ◆ icaltime_current_time_with_zone()

struct icaltimetype icaltime_current_time_with_zone | ( | const icaltimezone * | zone | ) |

Convenience constructor.

Returns
  The current time in the given timezone, as an icaltimetype.

## ◆ icaltime_day_of_week()

int icaltime_day_of_week | ( | const struct icaltimetype | t | ) |

Returns the day of the week of the given time.

Sunday is 1, and Saturday is 7.

## ◆ icaltime_days_in_month()

int icaltime_days_in_month | ( | const int | month,
|  | const int | year
| ) |  |

Returns the number of days in the given month.

## ◆ icaltime_days_in_year()

int icaltime_days_in_year | ( | const int | year | ) |

Returns the number of days in this year.

## ◆ icaltime_from_day_of_year()

struct icaltimetype icaltime_from_day_of_year | ( | const int | doy,
|  | const int | year
| ) |  |

Contructor.

Creates a new time, given a day of year and a year.

Note that Jan 1 is day #1, not 0.

## ◆ icaltime_from_string()

struct icaltimetype icaltime_from_string | ( | const char * | str | ) |

Contructor.

Creates a time from an ISO format string.

## ◆ icaltime_from_timet_with_zone()

struct icaltimetype icaltime_from_timet_with_zone | ( | const time_t | tm,
|  | const int | is_date,
|  | const icaltimezone * | zone
| ) |  |

Constructor.

Parameters

  tm | The time expressed as seconds past UNIX epoch
  is_date | Boolean: 1 means we should treat tm as a DATE
  zone | The timezone tm is in, NULL means to treat tm as a floating time

Returns a new icaltime instance, initialized to the given time, optionally using the given timezone.

If the caller specifies the is_date param as TRUE, the returned object is of DATE type, otherwise the input is meant to be of DATE-TIME type. If the zone is not specified (NULL zone param) the time is taken to be floating, that is, valid in any timezone. Note that, in addition to the uses specified in [RFC5545], this can be used when doing simple math on couples of times. If the zone is specified (UTC or otherwise), it's stored in the object and it's used as the native timezone for this object. This means that the caller can convert this time to a different target timezone with no need to store the source timezone.

## ◆ icaltime_is_date()

int icaltime_is_date | ( | const struct icaltimetype | t | ) |

Returns true if time is a DATE.

The options are DATE type, which returns true, or DATE-TIME, which returns false.

## ◆ icaltime_is_leap_year()

int icaltime_is_leap_year | ( | const int | year | ) |

Returns whether the specified year is a leap year.

Year is the normal year, e.g. 2001.

## ◆ icaltime_is_utc()

int icaltime_is_utc | ( | const struct icaltimetype | t | ) |

Returns true if the time is relative to UTC zone.

## ◆ icaltime_is_valid_time()

int icaltime_is_valid_time | ( | const struct icaltimetype | t | ) |

Returns false if the time is clearly invalid, but is not null.

This is usually the result of creating a new time type but not clearing it, or setting one of the flags to an illegal value.

## ◆ icaltime_normalize()

struct icaltimetype icaltime_normalize | ( | const struct icaltimetype | t | ) |

Normalizes the icaltime, so all of the time components are in their normal ranges.

For instance, given a time with minutes=70, the minutes will be reduces to 10, and the hour incremented. This allows the caller to do arithmetic on times without worrying about overflow or underflow.

## ◆ icaltime_null_date()

struct icaltimetype icaltime_null_date | ( | void |  | ) |

Constructor.

Returns
  A null date, which indicates no time has been set.

## ◆ icaltime_null_time()

struct icaltimetype icaltime_null_time | ( | void |  | ) |

Constructor.

Returns
  A null time, which indicates no time has been set. This time represents the beginning of the epoch.

## ◆ icaltime_set_timezone()

struct icaltimetype icaltime_set_timezone | ( | struct icaltimetype * | t,
|  | const icaltimezone * | zone
| ) |  |

Sets the timezone.

Forces the icaltime to be interpreted relative to another timezone. If you need to do timezone conversion, applying offset adjustments, then you should use icaltime_convert_to_zone instead.

## ◆ icaltime_span_contains()

int icaltime_span_contains | ( | icaltime_span * | s,
|  | icaltime_span * | container
| ) |  |

Returns true if the span is totally within the containing span.

Parameters

  s | The span to test for.
  container | The span to test against.

Returns
  boolean value.

## ◆ icaltime_span_new()

struct icaltime_span icaltime_span_new | ( | struct icaltimetype | dtstart,
|  | struct icaltimetype | dtend,
|  | int | is_busy
| ) |  |

Builds an icaltimespan given a start time, end time and busy value.

Parameters

  dtstart | The beginning time of the span, can be a date-time or just a date.
  dtend | The end time of the span.
  is_busy | A boolean value, 0/1.

Returns
  A span using the supplied values. The times are specified in UTC.

## ◆ icaltime_span_overlaps()

int icaltime_span_overlaps | ( | icaltime_span * | s1,
|  | icaltime_span * | s2
| ) |  |

Returns true if the two spans overlap.

Parameters

  s1 | First span to test
  s2 | Second span to test

Returns
  boolean value

The result is calculated by testing if the start time of s1 is contained by the s2 span, or if the end time of s1 is contained by the s2 span.

Also returns true if the spans are equal.

Note, this will return false if the spans are adjacent.

## ◆ icaltime_start_doy_week()

int icaltime_start_doy_week | ( | const struct icaltimetype | t,
|  | int | fdow
| ) |  |

Returns the day of the year for the first day of the week that the given time is within.

Returns the day of the year for the first day of the week .

This uses the first day of the week that contains the given time, which is a Sunday. It returns the day of the year for the resulting day.

## ◆ icaltime_today()

struct icaltimetype icaltime_today | ( | void |  | ) |

Convenience constructor.

Returns
  The current day as an icaltimetype, with is_date set.

## ◆ icaltime_week_number()

int icaltime_week_number | ( | const struct icaltimetype | t | ) |

Returns the week number for the week the given time is within.