datetime.h File Reference

Header file for date and time functions. More...

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Macros
#define	Y_M_D   0
	Date format: year, month, day.
#define	M_D_Y   1
	Date format: month, day, year.
#define	D_M_Y   2
	Date format: day, month, year.
#define	NO_DATE   -693594
	No date value.
#define	DATE_STR_SIZE   12
	Size of a date string.
#define	TIME_STR_SIZE   9
	Size of a time string.
#define	TIME_STAMP_SIZE   21
	Size of a time stamp string.

Typedefs
typedef double	DateTime
	Type for storing date and time values.

Functions
DateTime	datetime_encodeDate (int year, int month, int day)
	Encodes a date values from year, month, and day to a DateTime value.
DateTime	datetime_encodeTime (int hour, int minute, int second)
	Encodes a time value from hour, minute, and second to a DateTime value.
void	datetime_decodeDate (DateTime date, int *y, int *m, int *d)
	Decodes a DateTime value to year, month, and day.
void	datetime_decodeTime (DateTime time, int *h, int *m, int *s)
	Decodes a DateTime value to hour, minute, and second.
int	datetime_monthOfYear (DateTime date)
	Finds the month of the year for a date.
int	datetime_dayOfYear (DateTime date)
	Finds the day of the year for a date.
int	datetime_dayOfWeek (DateTime date)
	Finds the day of the week for a date.
int	datetime_hourOfDay (DateTime date)
	Finds the hour of the day for a time.
int	datetime_daysPerMonth (int year, int month)
	Finds the number of days in a month.
void	datetime_dateToStr (DateTime date, char *s)
	Converts a DateTime value to a string.
void	datetime_timeToStr (DateTime time, char *s)
	Converts a DateTime value to a string.
void	datetime_getTimeStamp (int fmt, DateTime aDate, int stampSize, char *timeStamp)
	Converts a DateTime value to a string.
int	datetime_findMonth (char *s)
	Finds the month of the year for a date.
int	datetime_strToDate (char *s, DateTime *d)
	Converts a string to a DateTime value.
int	datetime_strToTime (char *s, DateTime *t)
	Converts a string to a DateTime value.
void	datetime_setDateFormat (int fmt)
	Sets the date format.
DateTime	datetime_addSeconds (DateTime date1, double seconds)
	Adds seconds to a DateTime value.
DateTime	datetime_addDays (DateTime date1, DateTime date2)
	Adds days to a DateTime value.
long	datetime_timeDiff (DateTime date1, DateTime date2)
	Finds the difference in seconds between two DateTime values.

Detailed Description

Header file for date and time functions.

Author

L. Rossman

Date

Created: 2021-11-01

Last updated: 2024-12-30

Version

5.3.0

The DateTime type is used to store date and time values. It is equivalent to a double floating point type.

The integral part of a DateTime value is the number of days that have passed since 12/31/1899. The fractional part of a DateTime value is the fraction of a 24 hour day that has elapsed.

Update History

Build 5.1.011:

• New getTimeStamp function added.

Macro Definition Documentation

D_M_Y

#define D_M_Y   2

Date format: day, month, year.

DATE_STR_SIZE

#define DATE_STR_SIZE   12

Size of a date string.

M_D_Y

#define M_D_Y   1

Date format: month, day, year.

NO_DATE

#define NO_DATE   -693594

No date value.

TIME_STAMP_SIZE

#define TIME_STAMP_SIZE   21

Size of a time stamp string.

TIME_STR_SIZE

#define TIME_STR_SIZE   9

Size of a time string.

Y_M_D

#define Y_M_D   0

Date format: year, month, day.

Typedef Documentation

DateTime

DateTime

Type for storing date and time values.

Function Documentation

datetime_addDays()

DateTime datetime_addDays	(	DateTime	date1,
		DateTime	date2
	)

Adds days to a DateTime value.

Parameters

[in]	date1	Date value
[in]	days	Number of days to add

Returns

New DateTime value

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datetime_addSeconds()

DateTime datetime_addSeconds	(	DateTime	date1,
		double	seconds
	)

Adds seconds to a DateTime value.

Parameters

[in]	date1	Date value
[in]	seconds	Number of seconds to add

Returns

New DateTime value

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datetime_dateToStr()

void datetime_dateToStr	(	DateTime	date,
		char *	s
	)

Converts a DateTime value to a string.

Parameters

[in]	date	Date value
[out]	s	String to store the date

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datetime_dayOfWeek()

int datetime_dayOfWeek

(

DateTime

date

)

Finds the day of the week for a date.

Parameters

[in]

date

Date value

Returns

Day of week (0 = Sunday, 1 = Monday, ..., 6 = Saturday)

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datetime_dayOfYear()

int datetime_dayOfYear

(

DateTime

date

)

Finds the day of the year for a date.

Parameters

[in]

date

Date value

Returns

Day of year

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datetime_daysPerMonth()

int datetime_daysPerMonth	(	int	year,
		int	month
	)

Finds the number of days in a month.

Parameters

[in]	year	Year
[in]	month	Month

Returns

Number of days in the month

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datetime_decodeDate()

void datetime_decodeDate	(	DateTime	date,
		int *	y,
		int *	m,
		int *	d
	)

Decodes a DateTime value to year, month, and day.

Parameters

[in]	date	Date value
[out]	y	Year
[out]	m	Month
[out]	d	Day

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datetime_decodeTime()

void datetime_decodeTime	(	DateTime	time,
		int *	h,
		int *	m,
		int *	s
	)

Decodes a DateTime value to hour, minute, and second.

Parameters

[in]	time	Time value
[out]	h	Hour
[out]	m	Minute
[out]	s	Second

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datetime_encodeDate()

DateTime datetime_encodeDate	(	int	year,
		int	month,
		int	day
	)

Encodes a date values from year, month, and day to a DateTime value.

Parameters

[in]	year	Year
[in]	month	Month
[in]	day	Day

Returns

DateTime value

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datetime_encodeTime()

DateTime datetime_encodeTime	(	int	hour,
		int	minute,
		int	second
	)

Encodes a time value from hour, minute, and second to a DateTime value.

Parameters

[in]	hour	Hour
[in]	minute	Minute
[in]	second	Second

Returns

DateTime value

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datetime_findMonth()

int datetime_findMonth

(

char *

s

)

Finds the month of the year for a date.

Parameters

[in]

s

String date

Returns

Month of year

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datetime_getTimeStamp()

void datetime_getTimeStamp	(	int	fmt,
		DateTime	aDate,
		int	stampSize,
		char *	timeStamp
	)

Converts a DateTime value to a string.

Parameters

[in]	date	Date value
[in]	time	Time value
[out]	s	String to store the date and time

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datetime_hourOfDay()

int datetime_hourOfDay

(

DateTime

date

)

Finds the hour of the day for a time.

Parameters

[in]

time

Time value

Returns

Hour of day

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datetime_monthOfYear()

int datetime_monthOfYear

(

DateTime

date

)

Finds the month of the year for a date.

Parameters

[in]

date

Date value

Returns

Month of year

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datetime_setDateFormat()

void datetime_setDateFormat

(

int

fmt

)

Sets the date format.

Parameters

[in]

fmt

Date format

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datetime_strToDate()

int datetime_strToDate	(	char *	s,
		DateTime *	d
	)

Converts a string to a DateTime value.

Parameters

[in]	s	String date
[out]	d	DateTime value

Returns

1 if successful, 0 if not

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datetime_strToTime()

int datetime_strToTime	(	char *	s,
		DateTime *	t
	)

Converts a string to a DateTime value.

Parameters

[in]	s	String time
[out]	t	DateTime value

Returns

1 if successful, 0 if not

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datetime_timeDiff()

long datetime_timeDiff	(	DateTime	date1,
		DateTime	date2
	)

Finds the difference in seconds between two DateTime values.

Parameters

[in]	date1	First date value
[in]	date2	Second date value

Returns

Number of seconds

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datetime_timeToStr()

void datetime_timeToStr	(	DateTime	time,
		char *	s
	)

Converts a DateTime value to a string.

Parameters

[in]	time	Time value
[out]	s	String to store the time

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