I was mining one day, and found it annoying that I didn't know what time it was on the surface. Since carrying a clock around is inconvenient, (especially early game before I have gold) I decided to make a simple HUD element to fix it. The HUD shows the current progress through the day or night, and can be toggled on or off.
Modpack Policy: Clock HUD may by used in any modpack, public or private, without my explicit permission. You are required to remove Clock HUD from your modpack at my request.