Matlab's datenum () function usage
Converts a date and time for the date serial value
datenum function creates an array of values, each time point represents the number of days from January 0000 date of 0. Values also expressed in days past time. However, the best way to represent a time point data type is datetime use. It represents the best way is to use a past time or duration calendarDuration data types.
Date Number = datenum (t)
DateNumber = datenum(DateString)
DateNumber = datenum(DateString,formatIn)
DateNumber = datenum(DateString,PivotYear)
DateNumber = datenum(DateString,formatIn,PivotYear)
DateNumber = datenum (DateVector)
DateNumber datenum = (Y, M, D)
DateNumber datenum = (Y, M, D, H, MN, S)