Debugging Simple .bat That Worked On XP?

I have a backup .bat that I have hobbled together from forums such as this. The original was made a few years ago. It worked flawlessly, until I brought it to windows 7. Very funny, now, it only works between 10am and midnight. This has been hell to figure out because sometimes it works and sometimes it doesn't. I know it has something to do with the context of the "set hour" or "if "%hour.." part, but I can't figure it out. Should be an easy fix for someone familiar with .bat programming. Here is the relevant part:

Code: set hour=%time:~0,2%
if "%hour:0,1%"==" "set hour=0%time:~1,1%
set folder=%date:~10,4%_%date:~4,2%_%date:~7,2%-%hour%.%time:~3,2%
set DateFolder=%date:~10,4%_%date:~4,2%_%date:7,2%