Batch file,change filename with system date

I wrote a bat file like this, to change a file name, test.txt to testMonthDayYearTime.txt



here is what i wrote:
ren c:\example\test.txt test%date:~4,2%%date:~7,2%%date:~10,4%%time:~0,2%%time:~3,2%%time:~6,2%%.txt"


But after running, the file name is test12182010 093012.txt, a space is between date and time. I don;t want the space. Anyone know what's wrong.

or there is simple way to do this? thanks!