How do I get current date/time on the Windows command line in a suitable format for usage in a file/folder name?

Question

Update: Now that it\'s 2016 I\'d use PowerShell for this unless there\'s a really compelling backwards-compatible reason for it, particularly because of the regional setting

Answer 1

:: GetDate.cmd -> Uses WMIC.exe to get current date and time in ISO 8601 format
:: - Sets environment variables %_isotime% and %_now% to current time
:: - On failure, clears these environment variables
:: Inspired on -> https://ss64.com/nt/syntax-getdate.html
:: - (cX) 2017 adolfo.dimare@gmail.com
:: - http://stackoverflow.com/questions/203090
@echo off

set _isotime=
set _now=

:: Check that WMIC.exe is available
WMIC.exe Alias /? >NUL 2>&1 || goto _WMIC_MISSING_

if not (%1)==() goto _help
SetLocal EnableDelayedExpansion

:: Use WMIC.exe to retrieve date and time
FOR /F "skip=1 tokens=1-6" %%G IN ('WMIC.exe Path Win32_LocalTime Get Day^,Hour^,Minute^,Month^,Second^,Year /Format:table') DO (
    IF "%%~L"=="" goto  _WMIC_done_
        set _yyyy=%%L
        set _mm=00%%J
        set _dd=00%%G
        set _hour=00%%H
        set _minute=00%%I
        set _second=00%%K
)
:_WMIC_done_

::   1    2     3       4      5      6
:: %%G  %%H    %%I     %%J    %%K    %%L
:: Day  Hour  Minute  Month  Second  Year
:: 27   9     35      4      38      2017

:: Remove excess leading zeroes
        set _mm=%_mm:~-2%
        set _dd=%_dd:~-2%
        set _hour=%_hour:~-2%
        set _minute=%_minute:~-2%
        set _second=%_second:~-2%
:: Syntax -> %variable:~num_chars_to_skip,num_chars_to_keep%

:: Set date/time in ISO 8601 format:
        Set _isotime=%_yyyy%-%_mm%-%_dd%T%_hour%:%_minute%:%_second%
:: -> http://google.com/search?num=100&q=ISO+8601+format

if 1%_hour% LSS 112 set _now=%_isotime:~0,10% %_hour%:%_minute%:%_second%am
if 1%_hour% LSS 112 goto _skip_12_
    set /a _hour=1%_hour%-12
    set _hour=%_hour:~-2%
    set _now=%_isotime:~0,10% %_hour%:%_minute%:%_second%pm
    :: -> https://ss64.com/nt/if.html
    :: -> http://google.com/search?num=100&q=SetLocal+EndLocal+Windows
    :: 'if () else ()' will NOT set %_now% correctly !?
:_skip_12_

EndLocal & set _isotime=%_isotime% & set _now=%_now%
goto _out

:_WMIC_MISSING_
echo.
echo WMIC.exe command not available
echo - WMIC.exe needs Administrator privileges to run in Windows
echo - Usually the path to WMIC.exe is "%windir%\System32\wbem\WMIC.exe"

:_help
echo.
echo GetDate.cmd: Uses WMIC.exe to get current date and time in ISO 8601 format
echo.
echo    %%_now%%     environment variable set to current date and time
echo    %%_isotime%% environment variable to current time in ISO format
echo    set _today=%%_isotime:~0,10%%
echo.

:_out
:: EOF: GetDate.cmd