[Iska]

Попробуйте, например, так:

Код:

@echo off
setlocal

for /f "usebackq delims=" %%i in (
    `@"%systemroot%\system32\mshta.exe" "javascript:try {new ActiveXObject('Scripting.FileSystemObject').GetStandardStream(1).Write(new String(new Enumerator(new ActiveXObject('WbemScripting.SWbemLocator').ConnectServer('.', 'root\\cimv2').ExecQuery('SELECT LocalDateTime FROM Win32_OperatingSystem WHERE Primary = True')).item().LocalDateTime).substr(6, 2))}; catch (e){}; close();" ^
    1^|more`
) do set sDay=%%i

if defined sDay if %sDay% equ 15 (
	echo Something to do...
) else (
	echo Something other...
)

endlocal
exit /b 0