DateDiff,  Version 1.02
Batch tool calculate the timespan between two specified dates

Usage:    DATEDIFF  date  date  [ option ]

Where:    "date"    is a date/time in local or ISO date/time format, or "Now"
          "option"  can be one of the following switches:
                    /A    return only the sign of the timespan (+ or -)
                    /D    return total number of entire Days in timespan
                    /H    return total number of entire Hours in timespan
                    /I    return total number of mIlliseconds in timespan
                    /M    return total number of entire Minutes in timespan
                    /R    return Raw timespan string (+/-dd.hh:mm:ss.iii000000)
                    /S    return total number of entire Seconds in timespan
                    /T    return total number of Ticks in timespan
                    /V    Verbose output string, including leading and trailing
                          zeroes (e.g. 0 years, or 0 milliseconds)
                    /W    return total number of entire Weeks in timespan
                    /Y    return number of entire Years in timespan

Notes:    Dates must be entered either in YYYY-MM-DD [hh:mm[:ss[.iii]]] format,
          or in local system's date/time format with DOT for decimal delimiter,
          or as "Now", in which case the current date and time will be used.
          In both dates, date and time components are optional, but at least
          one of these must be specified: if no date is specified, today is
          assumed, if no time is specified, 00:00:00.000000000 is assumed.
          Default output: years, days, hours, minutes, seconds, milliseconds;
          first value shown will be first non-zero value, unless /V specified;
          milliseconds will not be shown if zero, unless /V or /I is specified.
          Return code ("ErrorLevel") equals absolute value of the result for
          /D or /H or /M or /S or /W or /Y switches; otherwise 0 if result is
          valid or 1 in case of (command line) errors.

Written by Rob van der Woude
http://www.robvanderwoude.com