Clock-watching
Here is a link to a results page for a search for "clock-watching." t.ly/WQyqx
I think I could be termed a clock-watcher. I tend to anticipate a coming event. I often get ready too early but I picture being just on time, not early. I tend to compare clocks around the house and other sources of the current time, such as internet-connected devices and the web page at time.gov.
I have seen cartoons about being late and the difficulties such a habit can create but I haven't seen much about being early.
I was impressed by a grad school course that was about human minds and habits when the subject of astronomical observations came up. The personal differences in habits and speed of recognition and recording an event needed to be recognized.