__pmParseTime man page
__pmParseTime — parse time point specification
int __pmParseTime(const char *string, struct timeval *logStart, struct timeval *logEnd, struct timeval *rslt, char **errMsg);
cc ... -lpcp
__pmParseTime is designed to encapsulate the interpretation of a time point specification in command line switches for use by the PCP client tools.
This function expects to be called with the time point specification as string. If the tool is running against PCP archive(s), you also need to supply the start time of the first (only) archive as logStart, and the end of the last (only) archive as logEnd. See pmGetArchiveLabel(3) and pmGetArchiveEnd(3) for how to obtain values for these parameters. If the tool is running against a live feed of performance data, logStart should be the current time (but could be aligned on the next second for example), while logEnd should have its tv_sec component set to INT_MAX.
The rslt structure must be allocated before calling __pmParseTime.
You also need to set the current PCP reporting time zone to correctly reflect the -z and -Z command line parameters before calling __pmParseTime. See pmUseZone(3) and friends for information on how this is done.
If the conversion is successful, __pmParseTime returns 0, and fills in rslt with the time value defined by the input parameters. If the argument strings could not be parsed, it returns -1 and a dynamically allocated error message string in errMsg. Be sure to free(3) this error message string.
PMAPI(3), pmGetArchiveEnd(3), pmGetArchiveLabel(3), pmNewContextZone(3), pmNewZone(3), pmParseInterval(3), pmParseTimeWindow(3), pmUseZone(3), __pmConvertTime(3) and __pmParseCtime(3).