In a solar return chart.....since the Sun moves 1 degree per day ,does this mean that the horizon does also?

You progress the Ascendant, MC, Sun , Moon or any planet so that it can make an important aspect to a natal planet. The reason is simple. If THAT aspect repeats an aspect in the natal chart, you can safely say that an important event will arise. Calculate the number of degrees that completes the aspect and convert into months. Any progressions inside a Solar return is not like symbolic or secondary progressions. One degree = 1 month of time. Or, 2 hours = 1 month and 4 min = 1 day of time. Any important aspects has to be activated by a Lunar aspect at the same time. Note that you can have 20 aspects and not one will be realized unless they repeat themself are backed by a Transit, and aspected by the Moon