Did you put this in addons? Like are you sure you didn't have it like:
gmod/addons/MYADDON/MYADDON/files??
Because I know a lot of people who do that...
Oh I think I figured out the problem. Your folder format inside the download is slightly different from others and you have it nested inside of the root folder in directory called lua, which contains the addon.txt and relevant files. So I should put the LUA folder into the addons folder, not the containing folder (ulx set Utime) . Oops. I thought I was better than this! Sorry to waste your time!
Edit:
This is what I get for jumping on the forums without some morning caffeine. I misread the folder structure in your compressed file download. After re-chcking the FTP folder structure, it's correct. The addon.txt, with it's containing lua folder are in a folder like this: garrysmod/addons/ulx set Utime/addon.txt with a subfolder of 'lua'. It's not working like this for some reason, and i'm not sure why. It's not listed in the ULX loading reports, nor do I have any options for it once I open the GUI.
So apparently it's not starting at all.
Further edit:
I went through and compared the folder structures of both the ULX addon itself, and the change utime folders, and yours looks like it's correct. I'm mystified why it's not loading. What are common reasons for ulx addons not even showing up in the loading status?