Time management

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Detailed Description

Time function handle time calculations and daylight saving time (DST).

DST rules are recorded in the file tzinfo.txt. The file loaded is the first found according the following search sequence:

• The current directory
• The same directory as the executable gridlabd.exe
• The path in the GLPATH environment variable

DST rules are recorded in the Posix-compliant format for the TZ environment variable:

        STZ[hh[:mm][DTZ][,M#[#].#.#/hh:mm,M#[#].#.#/hh:mm]]

Defines
#define	DAY   (86400*TS_SECOND)
	the number of ticks in one day
#define	HOUR   (3600*TS_SECOND)
	the number of ticks in one hour
#define	MICROSECOND   (TS_SECOND/1000000)
	the number of ticks in one microsecond
#define	MINUTE   (60*TS_SECOND)
	the number of ticks in one minute
#define	SECOND   (TS_SECOND)
	the number of ticks in one second
Typedefs
typedef struct s_datetime	DATETIME
	the s_datetime structure
Functions
TIMESTAMP	compute_dstevent (int year, SPEC *spec, time_t offset)
	Computes the GMT time of a DST event Offset indicates the time offset to include.
int	convert_from_timestamp (TIMESTAMP ts, char *buffer, int size)
	Convert from a timestamp to a string.
TIMESTAMP	convert_to_timestamp (char *value)
	Convert from a string to a timestamp.
int	isdst (TIMESTAMP t)
	Determine whether a GMT timestamp is under DST rules.
void	load_tzspecs (char *tz)
	Load a timezone from the timezone info file.
int	local_datetime (TIMESTAMP ts, DATETIME *dt)
	Converts a GMT timestamp to local datetime struct Adjusts to TZ if possible.
int	local_tzoffset (TIMESTAMP t)
	Calculate the current TZ offset in seconds.
TIMESTAMP	mkdatetime (DATETIME *dt)
	Convert a datetime struct into a GMT timestamp.
void	set_tzspec (int year, char *tzname, SPEC *pStart, SPEC *pEnd)
	Apply a timezone spec to the current tz rules.
int	strdatetime (DATETIME *t, char *buffer, int size)
	Convert a datetime struct to a string.
char *	timestamp_current_timezone (void)
	Read the current timezone specification.
char *	timestamp_set_tz (char *tz_name)
	Establish the default timezone for time conversion.
int	timestamp_test (void)
	Test the daylight saving time calculations.
int	timestamp_year (TIMESTAMP ts, TIMESTAMP *remainder)
	Determine the year of a GMT timestamp Apply remainder if given.
char *	tz_dst (char *tzspec)
	Get the std timezone name.
int	tz_info (char *tzspec, char *tzname, char *std, char *dst, time_t *offset)
	Extract information from an ISO timezone specification.
char *	tz_name (char *tzspec)
	Converts a timezone spec into a standard timezone name Populate tzspec if provided, otherwise returns a static buffer.
time_t	tz_offset (char *tzspec)
	Compute the offset of a tz spec.
char *	tz_std (char *tzspec)
	Get the std timezone name.

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Function Documentation

char * timestamp_current_timezone

(

void

)

Read the current timezone specification.

Returns:

a pointer to the first character in the timezone spec string

Definition at line 74 of file timestamp.c.

Referenced by cmex_get().

char * timestamp_set_tz

(

char *

tz_name

)

Establish the default timezone for time conversion.

NULL tzname uses TZ environment for default

Definition at line 647 of file timestamp.c.

References load_tzspecs(), and throw_exception().

Referenced by exec_init().

int timestamp_test

(

void

)

Test the daylight saving time calculations.

Returns:

the number of test the failed

Definition at line 830 of file timestamp.c.

References convert_from_timestamp(), convert_to_timestamp(), DAY, FMT_INT64, HOUR, local_datetime(), mkdatetime(), output_test(), output_verbose(), SECOND, and strdatetime().

Referenced by cmdarg_load().