-char * ctime( const time_t * tod );
-double difftime( time_t t1, time_t t0 );
-struct tm * gmtime( const time_t * tod );
-struct tm * localtime( const time_t * tod );
-time_t mktime( struct tm * tptr );
-size_t strftime( char * restrict s, size_t n, const char * restrict format,
- const struct tm * restrict tptr );
-time_t time( time_t * tod );
-
-#endif // __TIME_H
+
+/* Returns the difference between two calendar times in seconds. */
+double difftime( time_t time1, time_t time0 );
+
+/* Normalizes the values in the broken-down time pointed to by timeptr.
+ Returns the calender time specified by the broken-down time.
+*/
+time_t mktime( struct tm * timeptr );
+
+/* Returns the current calender time. If timer is not a NULL pointer, stores
+ the current calender time at that address as well.
+*/
+time_t time( time_t * timer );
+
+/* Sets the interval pointed to by ts to the current calender time, based
+ on the specified base.
+ Returns base, if successful, otherwise zero.
+*/
+int timespec_get( struct timespec * ts, int base );
+
+/* Converts the broken-down time pointed to by timeptr into a string in the
+ form "Sun Sep 16 01:03:52 1973\n\0".
+*/
+char * asctime( const struct tm * timeptr );
+
+/* Equivalent to asctime( localtime( timer ) ). */
+char * ctime( const time_t * timer );
+
+/* Converts the calender time pointed to by timer into a broken-down time
+ expressed as UTC.
+ Returns a pointer to the broken-down time, or a NULL pointer if it
+ cannot be represented.
+*/
+struct tm * gmtime( const time_t * timer );
+
+/* Converts the calender time pointed to by timer into a broken-down time
+ expressed as local time.
+ Returns a pointer to the broken-down time, or a NULL pointer if if
+ cannot be represented.
+*/
+struct tm * localtime( const time_t * timer );
+
+/* Writes the broken-down time pointed to by timeptr into the character
+ array pointed to by s. The string pointed to by format controls the
+ exact output. No more than maxsize charactrs will be written.
+ Returns the number of characters written (excluding the terminating
+ null character), or zero on failure.
+*/
+size_t strftime( char * _PDCLIB_restrict s, size_t maxsize, const char * _PDCLIB_restrict format, const struct tm * _PDCLIB_restrict timeptr );
+
+#endif