IntelĀ® Trace Collector 9.1 Update 2 User and Reference Guide
double VT_timestamp (void)
In contrast to previous versions, this time stamp no longer represents seconds. Use VT_timeofday() for that instead. The result of VT_timestamp() can be copied verbatim and given to other API calls, but nothing else.
DOUBLE PRECISION VTSTAMP()
Returns an opaque time stamp, or VT_ERR_NOTINITIALIZED.