When you're in the zone, it's easy to lose track of time, forget to take breaks, and forget how long you've been working. Reader Alejandro decided to use Windows' built-in wallpaper rotation feature and some colour-coded wallpapers to keep track of time, and he made the pack free to download.
The setup is simple — just download the pack of wallpapers from Alejandro's DeviantArt page, keep them in a folder, and then tell Windows to rotate through that folder for wallpapers every 30 minutes. Windows will start from the lowest filename to the highest (as long as you don't tell it to shuffle, and you shouldn't.) You'll start your four hour cycle with a cool blue wallpaper, and then every 30 minutes the wallpaper will change colour to indicate that time is passing and you may want to take a break.
The image above shows you the wallpaper colours based on the amount of time that's progressed, and you'll know a full four hours has passed when your wallpaper has moved from that cool blue to a warm orange and finally a deep red. The wallpaper pack is also labelled with the amount of time that's passed, so if you minimize all of the windows, you'll see a big "X hours" in your desktop, just as a reminder. Hit the link below to grab them in your preferred desktop size, 1920 by 1080, or 3480 by 1080.
Modern UI Productivity Wallpapers [DeviantArt] Thanks to Alejandro for sending in the tip!