Man Pages – Linux Manual Pages

difftime – calculate time difference
USAGE
#include <time.h>

double difftime(time_t time1, time_t time0);

DESCRIPTION
The difftime() function returns the number of seconds elapsed between
time time1 and time time0, represented as [...]

date – print or set the system date and time
USAGE
date [OPTION]… [+FORMAT]
date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]

DESCRIPTION
Display the current time in the given FORMAT, or set the system date.

-d, –date=STRING
[...]

co – check out RCS revisions
USAGE
co [options] file …

DESCRIPTION
co retrieves a revision from each RCS file and stores it into the cor-
responding working file.

Pathnames matching an [...]

ASCII
USAGE
#include <time.h>

char *asctime(const struct tm *tm);
char *asctime_r(const struct tm *tm, char *buf);

char *ctime(const time_t *timep);
char *ctime_r(const time_t *timep, char *buf);

[...]