AT Job zu einem beliebigen (unbekannten) Zeitpunkt in Minuten per Script starten

:: Start meiner Zeitadditionsbatch mit dem Parameter 12 (Minuten).
:: Die Batch timeadd.cmd soll dabei eine Umgebungsvariable newTime erzeugen, die die aktuelle Zeit plus 12 Minuten
:: errechnet, d. h. auch ggfs. den Stunden- und Tages-Wechsel beinhaltet (manche Scripts laufen auch Nachts... :-))
call %~dp0\timeadd.cmd 12

:: Aufruf des AT Befehls mit der neuen Umgebungsvariable
at %newTime% /interactive "notepad.exe"  

@echo off
goto START

************************************************************************************
* Create a own time variable 'newTime'.     
*
* You can add some minutes (0-59) to your local time, write this new time in a     
* variable 'newTime' and use the variable as parameter for AT (or something else).     
*                                                                                  
* Start: timeadd <min>                                                            
*         minutes between 0 and 59                                                 
*                                                                                  
* Preparations: 	OS = Windows XP                                            
*                                                                                  
************************************************************************************

:START
set zeit="%time%"  

if "%1" == "" goto DELAY  

set factor=%1
goto TIMEADD

:DELAY
echo Input time delay between 1 and 59:
set /P factor=

if %factor% GTR 59 goto DELAY_ERR
goto TIMEADD


:TIMEADD
if %factor% GTR 59 goto DELAY_ERR
echo **************** Calculations ************************
echo.
echo Actual Time: %zeit%
echo.

For /F "Tokens=1,2 Delims=:" %%J In (%zeit%) Do (  
     Set hour=%%J
     Set minutes=%%K
   ) 

set /A newminutes=("factor" + "minutes")  

if %newminutes% GTR 59 goto MAXMINUTE
set newTime=%hour%:%newminutes%
goto END


:MAXMINUTE
set /A newminutesless=("newminutes" - "60")  
set /A newhourplus=("hour" + "1")  

if (%newhourplus% GTR 23) set newhourplus=0

set newTime=%newhourplus%:%newminutesless%
goto END

:DELAY_ERR
goto DELAY


:END
echo.
echo Time delay: %factor%
echo.
echo New Time: %newTime%

set newhourplus=
set hour=
set newminutes=
set factor=
set newminutesless=
set minutes=
set zeit=