Microtime gets the current Unix timestamp and microsecond number

microtime-returns the current Unix timestamp and microseconds description

Mixed Microtime ([bool $get _as_float])

Microtime () The current Unix timestamp and the number of microseconds. This function is only available under an operating system that supports Gettimeofday () system calls.

If invoked without an optional argument, this function returns a string in the format "msec sec", where the SEC is the number of seconds since the Unix era (0:00:00 January 1, 1970 GMT), and the msec is the microsecond portion. Both parts of a string are returned in seconds.

If the Get_as_float parameter is given and its value is equivalent to True,microtime (), a floating-point number is returned.
For example:

Echo Microtime (); 0.36682300 1512725230
Echo microtime (true);//1512725230.3668