Calendar time

Calendar arithmetic independent of the time zone and the RTC. More...

Macros
#define	PBL_TM_YEAR_ORIGIN   1900
	Year that tm_year in struct tm counts from.
#define	PBL_EPOCH_YEAR   1970
	Year of the Unix epoch.
#define	PBL_EPOCH_WDAY   4
	Day of the week of the Unix epoch (Thursday), as an enum pbl_weekday value.

Enumerations
enum	pbl_weekday {   PBL_SUNDAY = 0 , PBL_MONDAY , PBL_TUESDAY , PBL_WEDNESDAY ,   PBL_THURSDAY , PBL_FRIDAY , PBL_SATURDAY }
	Day of the week, numbered like tm_wday. More...

Functions
static bool	pbl_time_is_weekday (enum pbl_weekday day)
	Check whether a day is a working day (Monday to Friday).
static bool	pbl_time_is_weekend (enum pbl_weekday day)
	Check whether a day is on the weekend (Saturday or Sunday).
bool	pbl_time_is_leap_year (int year)
	Check whether a Gregorian year is a leap year.
int	pbl_time_days_in_month (int month, bool is_leap_year)
	Get the number of days in a month.
void	pbl_time_split_seconds (uint32_t seconds, uint32_t *days, uint32_t *hours, uint32_t *minutes, uint32_t *secs)
	Split a duration into days, hours, minutes and seconds.
int	pbl_time_display_hour (int hour, bool is_24h)
	Convert an hour of the day to the hour shown on a clock.
int	pbl_time_minute_of_day_adjust (int minute, int delta)
	Add a delta to a minute of the day, wrapping around midnight.
void	pbl_time_breakdown (time_t t, struct tm *tm)
	Fill the calendar fields of a struct tm from seconds since the epoch.

Detailed Description

Calendar arithmetic independent of the time zone and the RTC.

Macro Definition Documentation

PBL_EPOCH_WDAY

#define PBL_EPOCH_WDAY   4

Day of the week of the Unix epoch (Thursday), as an enum pbl_weekday value.

PBL_EPOCH_YEAR

#define PBL_EPOCH_YEAR   1970

Year of the Unix epoch.

PBL_TM_YEAR_ORIGIN

#define PBL_TM_YEAR_ORIGIN   1900

Year that tm_year in struct tm counts from.

Enumeration Type Documentation

pbl_weekday

enum pbl_weekday

Day of the week, numbered like tm_wday.

Enumerator
PBL_SUNDAY	Sunday.
PBL_MONDAY	Monday.
PBL_TUESDAY	Tuesday.
PBL_WEDNESDAY	Wednesday.
PBL_THURSDAY	Thursday.
PBL_FRIDAY	Friday.
PBL_SATURDAY	Saturday.

Function Documentation

pbl_time_breakdown()

void pbl_time_breakdown	(	time_t	t,
		struct tm *	tm
	)

Fill the calendar fields of a struct tm from seconds since the epoch.

Sets tm_sec to tm_yday. The DST, offset and zone fields are left untouched.

Parameters

	t	Seconds since the Unix epoch.
[out]	tm	Broken-down time.

pbl_time_days_in_month()

int pbl_time_days_in_month	(	int	month,
		bool	is_leap_year
	)

Get the number of days in a month.

Parameters

month	Month of the year, 1 (January) to 12 (December).
is_leap_year	Whether the year is a leap year.

Returns

Number of days, 28 to 31.

pbl_time_display_hour()

int pbl_time_display_hour	(	int	hour,
		bool	is_24h
	)

Convert an hour of the day to the hour shown on a clock.

Parameters

hour	Hour of the day, 0 to 23.
is_24h	Whether the clock uses the 24-hour format.

Returns

hour on a 24-hour clock, or 1 to 12 on a 12-hour clock.

pbl_time_is_leap_year()

bool pbl_time_is_leap_year

(

int

year

)

Check whether a Gregorian year is a leap year.

Parameters

year	Full year, e.g. 2024.

Returns

true for a leap year.

pbl_time_is_weekday()

static bool pbl_time_is_weekday ( enum pbl_weekday  day )

inlinestatic

Check whether a day is a working day (Monday to Friday).

Parameters

day	Day of the week.

Returns

true for Monday to Friday.

References PBL_FRIDAY, and PBL_MONDAY.

pbl_time_is_weekend()

static bool pbl_time_is_weekend ( enum pbl_weekday  day )

inlinestatic

Check whether a day is on the weekend (Saturday or Sunday).

Parameters

day	Day of the week.

Returns

true for Saturday and Sunday.

References PBL_SATURDAY, and PBL_SUNDAY.

pbl_time_minute_of_day_adjust()

int pbl_time_minute_of_day_adjust	(	int	minute,
		int	delta
	)

Add a delta to a minute of the day, wrapping around midnight.

Parameters

minute	Minute of the day, 0 to 1439.
delta	Minutes to add, at most one day in either direction.

Returns

Adjusted minute of the day, 0 to 1439.

pbl_time_split_seconds()

void pbl_time_split_seconds	(	uint32_t	seconds,
		uint32_t *	days,
		uint32_t *	hours,
		uint32_t *	minutes,
		uint32_t *	secs
	)

Split a duration into days, hours, minutes and seconds.

Parameters

	seconds	Duration in seconds.
[out]	days	Whole days.
[out]	hours	Remaining hours, 0 to 23.
[out]	minutes	Remaining minutes, 0 to 59.
[out]	secs	Remaining seconds, 0 to 59.