The news article about the falling comet was in a newspaper from New York City, New York. This city is in the Eastern time zone. Colorado Springs, Colorado is in the mountain time zone. The newspaper article predicted that the comet would hit at midnight. Since it was based in the Eastern time zone, the comet was predicted at 10 pm Colorado time.
This show likely portrays the great Halley's Comet panic of 1910.
When Robert E and Grace visit the clinic at night, there is a sound of a big bell sounding. The town does not have a bell with that deep sound.