Copy the "Block" sprite to your backpack. Or simply grab the scripts that are contained within. Click the purple "SetLockout" script, then delete it, if you like, so it's completely hidden from view. If you delete the "SetLockout" script, you'll need to pull it from your backpack to update the "TimeAllowed" variable, next time you save your game. You can paint a new "Warning" screen, and rename that as well. Just make sure the lockout script points to the right name for it. You don't need the "Info" sprite to use this at all.
I'm not really a fan of this sorta thing, but I saw it referenced on the Scratch wiki page, and thought the scripts looked a bit complicated. It was dividing tolerance by 1000, when there are actually 1440 minutes per day. So it made more sense to do it this way, instead of telling the user to multiply numbers by 1.44