When the input strings to MATLAB functions of DATENUM, DATEVEC,and STR2NUM are very large, these functions are very intolerably slow (try for example the datenum with 100 yrs of hourly date string). FDATENUM, FDATEVEC, FSTR2NUM are fast counterparts of these MATLAB functions. The fastness owns a divide-and-conquer strategy, as comes as another function in this package, DIVCONQ. See FDATE_DEMO for a demonstration and the documents in the individual functions.