To visualize the time of day, I used the sun and moon. Each day hour, the sun moves and each night hour, the moon moves. You can tell the time by looking at the placement and whether it's the sun or moon (or the sunrise/sunset). You can also tell the live second by looking at the top cloud and the minute by looking at the bottom cloud.
reference:
http://creative-coding.decontextualize.com/changes-over-time/