Well..during the course of the year, the sunset position moves northward between the Summer Solstice and the Winter Solstice. It moves southward between the Winter Solstice and the Summer Solstice. The rate at which it moves depends on the time of the year since the earth moves faster towards the Winter Solstice than the Summer Solstice. The actual rates are about 0.1 degrees per day so that its position shifts about 1/3 diameter per day or so. But this is just an estimate ( 26 degrees/180 days). You will need an ephemeris generated by any of a large variety of planetaria simulators to get the rates appropriate to your location and time of year.