In tip 721, we scripted a general purpose Date Math routine.

JSITimeM.bat is a general purpose Time Math routine which is called with the following syntax:

JSItimeM \[HH1 MM1 +/- HH2 MM2\]

When called without parameters, JSITimeM returns the following environment variables (your system must be configured for a 24 hour clock):

AHH	is the current hour.
AMM	is the current minute.
NHH	is a numeric variable that contains the current hour.
NMM	is a numeric variable that contains the current minute.
NSEC	is a numeric variable which contains the number of seconds since mid-night.

When called with parameters, JSITimeM returns:

AHH	is the resultant hour. The range is 00 - 23.
AMM	is the resultant minute. The range is 00 - 59.
NHH	is a numeric variable that contains the resultant hour.
NMM	is a numeric variable that contains the resultant minute.
NSEC	is a numeric variable which contains the resultant number of seconds.  A value of 999999 indicates an error in the parameters.  If it is greater than 86399, the time returned is the next day.  If negative, time2 was later than time1 during a subtraction.

Examples:

- To return the current time:

     call JSITimeM

- To cause a batch job to sleep until 05:00 PM, unless it is already later:

     call JSITimeM
     call JSITimeM 17 00 - %AHH% %AMM%
     if %NSEC% EQU 999999 goto error
     if %NSEC% LSS 0 goto continue
     sleep %NSEC%
     :continue

JSITimeM.bat contains:

@echo off
set NSEC=
set NEG=N
if /i "%3"
"+" goto OK1
If /i "%3"
"-" goto OK1
if "%3"
"" goto OK1
:syntax
@echo JSITimeM \[HH1 MM1 +/- HH2 MM2\]
set /a NSEC=999999
set N1HH=
set N1MM=
set N2HH=
set N2MM=
set NEG=
goto end
:OK1
if not "%1"
"" goto OK2
for /f "Tokens=1,2 Delims=:" %%i in ('time /t') do call :now %%i %%j
goto end
:now
set AMM=%2
set NHH="%1"
set NMM="%2"
set NHH=%NHH:"=%
set /a NHH=100%NHH%%%100
set AHH=%NHH%
if not %NHH% GTR 9 set AHH=0%AHH% 
set NMM=%NMM:"=%
set /a NMM=100%NMM%%%100
set /a NSEC=%NHH%*3600
set /a WSEC=%NMM%*60
set /a NSEC=%NSEC% + %WSEC%
set WSEC=
goto end
:OK2
if "%5"
"" goto syntax
set N1HH="%1"
set N1HH=%N1HH:"=%
set /a N1HH=100%N1HH%%%100
set N1MM="%2"
set N1MM=%N1MM:"=%
set /a N1MM=100%N1MM%%%100
set N2HH="%4"
set N2HH=%N2HH:"=%
set /a N2HH=100%N2HH%%%100
set N2MM="%5"
set N2MM=%N2MM:"=%
set /a N2MM=100%N2MM%%%100
if %N1HH% GTR 23 goto syntax 
if %N2HH% GTR 23 goto syntax 
if %N1MM% GTR 59 goto syntax 
if %N2MM% GTR 59 goto syntax 
If /i "%3"
"-" goto OK8
set /a W1SEC=%N1HH%*3600
set /a W2SEC=%N1MM%*60
set /a NSEC=%W1SEC% + %W2SEC%
set /a W1SEC=%N2HH%*3600
set /a W2SEC=%N2MM%*60
set /a NSEC=%NSEC% + %W1SEC% + %W2SEC%
if %NSEC% GTR 86399 set /a NHH=(%NSEC% - 86400)
:OK3
set /a NHH=%NSEC%/3600
set /a W1SEC=%NHH%*3600
set /a W2SEC=%NSEC% - %W1SEC%
set /a NMM=%W2SEC/60
if %NHH% GTR 9 goto OK4
set AHH=0%NHH%
goto OK5
:OK4
set AHH=%NHH%
:OK5
if %NMM% GTR 9 goto OK6
set AMM=0%NMM%
goto OK7
:OK6
set AMM=%NMM%
:OK7
if "%NEG%"=="N" goto OK7A
set /a NSEC=0-%NSEC%
:OK7A
set N1HH=
set N1MM=
set N2HH=
set N2MM=
set W1SEC=
Set W2SEC=
set NEG=
goto end
:OK8
set /a W1SEC=%N1HH%*3600
set /a W2SEC=%N1MM%*60
set /a NSEC=%W1SEC% + %W2SEC%
set /a W1SEC=%N2HH%*3600
set /a W2SEC=%N2MM%*60
set /a NSEC=%NSEC% - %W1SEC% - %W2SEC%
if %NSEC% LSS 0 goto OK9
goto OK3
:OK9
set NEG=Y
set /a NSEC=0-%NSEC%
set /a NSEC=86400 - %NSEC%
goto OK3
:end