Date2Secs

Date2Secs Convert a DateTimeRec into a "raw" seconds value

#include <OSUtils.h> Operating System Utilities

void Date2Secs(dtrp, secs );

DateTimeRec *dtrp ; contains day, month, year, hour, etc.

unsigned long *secs ; receives "raw" seconds since 1/1/1904

Date2Secs converts the fields of a DateTimeRec into a "raw" seconds value.

The result could be used in comparing two dates or setting the clock.

dtrp is the address of a 14-byte DateTimeRec structure. The dayOfWeek

field is ignored. The other fields are used (in a flexible manner) to

calculate the value for secs.

secs is the address of a 4-byte unsigned long int. Upon return, it will

contain a "raw" seconds value corresponding to the values of the

fields in the DateTimeRec addressed by dtrp.

Notes: Date2Secs is a handy intermediate step for generating a textual

representation of a date (see IUDateString). It is also useful for adding,

subtracting, or comparing two dates/times. For instance:

# define SECS_PER_DAY (60*60*24)

DateTimeRec ivcDate, shipDate;

unsigned long ivcSecs, shipSecs;

short elapsedDays;

Date2Secs( &ivcDate, &ivcSecs);

Date2Secs( &shipDate, &shipSecs);

elapsedDays = (shipSecs-ivcSecs)/SECS_PER_DAY;

Although the year and month fields of the DateTimeRec should be valid, this

call is flexible about other fields. Thus, you can convert an "invalid" date

(such as January 200 or today+30) to "raw" seconds, and back to date/time

to make it valid. For instance:

DateTimeRec theDate = {1989, 3,15 }; /* March 15 */

theDate.day +=30; /* March 45 */

Date2Secs( &theDate, &secs);

Secs2Date( secs, &theDate); /* April 14 */

Since the base date for the any "raw seconds" value is 1/1/1904 and since

secs is a 32-bit value, you won't be able to calculate with dates beyond

Feb. 6, 2040.

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