You can select start date, end date and number of days between each calculation, and the time when position are calculated. Beware calculation time if to much date are selected. This screen show you the morning and evening twilight time for each date you select. Nautical twilight is when Sun is 12 degrees below horizon.
Brighter stars are visible.
Astronomical twilight is when Sun is 18 degrees below horizon. Sky is dark and all stars are visible. Show the position, magnitude, apparent diameter, illuminated fraction, rise, culmination and set time for the planets, the Moon and the Sun for each selected date. The elevation above horizon and azimuth at the twilight time are indicated to help observing comets near the Sun. This indicate if the comet is best on the morning or evening.