On the command line, note: must copy and paste below lines of code and then execute them one by one:
FOR /f %a IN ('WMIC OS GET LocalDateTime ^| FIND "."') DO SET DTS=%a
SET DateTime=%DTS:~0,4%-%DTS:~4,2%-%DTS:~6,2%_%DTS:~8,2%-%DTS:~10,2%-%DTS:~12,2%
echo %DateTime%
In a BAT file:
@echo off
REM See http://*.com/q/1642677/1143274
FOR /f %%a IN ('WMIC OS GET LocalDateTime ^| FIND "."') DO SET DTS=%%a
SET DateTime=%DTS:~0,4%-%DTS:~4,2%-%DTS:~6,2%_%DTS:~8,2%-%DTS:~10,2%-%DTS:~12,2%
echo %DateTime%
Example output:
2016-08-26_22-21-15