Leading Zeros In A Batch Timestamp

:prepare time stamp
set year=%date:~10,4%
set month=%date:~4,2%
set day=%date:~7,2%
set hour=%time:~0,2%
:replace leading space with 0 for hours < 10
if "%hour:~0,1%" == " " set hour=0%hour:~1,1%
set minute=%time:~3,2%
set second=%time:~6,2%
set timeStamp=%year%_%month%_%day%_%hour%_%minute%_%second%

rem Proof: https://www.ezrasf.com/wplog/2014/01/23/leading-zeros-in-a-batch-timestamp/