There are practical uses. In particular, crops need to be planted at certain times in the seasonal cycle. Where crops need to be planted before the wet season starts, it's very useful to be able to predict when the wet season will start. Astronomy can help. Astronomy-based calendars were used to time agricultural activities in a number of cultures, in Mesopotamia, around the Mediterranean, and in sub-Saharan Africa. One famous example is the Egyptian use of the heliacal rising of Sirius to predict the Nile floods (which, due to the 26,000 year precession of the equinoxes, was out by 10 days after 700 years).

Astronomy can also help keep the calendar synchronised across a culture. This is particularly the case when a lunar calendar is used, and the 12th month ends at about the end of the year. Is the next month the 13th month, or the 1st month?

As for religion, there are multiple religious uses of astronomy. If the sun, moon, and planets are identified with gods, then observing their motion can be a religious activity, even if of no practical use. There are "practical" religious uses, too. If it is important for religious festivals to be held on certain dates, then an astronomically-based accurate calendar is important. (This was an important motivator for astronomy in the Islamic world.) The stars and planets can also be a medium by which the gods speak to humans - if the humans know how to read the messages. This can be considered a variety of astrology, but is perhaps better described as reading celestial omens.

Which leads to astrology, predicting the future, or learning about the present, from the stars and planets. If one removes the above idea of messages from the gods, then one is left with a non-religious magical practice. While modern scientific opinion holds that astrology is devoid of real value, ancient scientific opinion often held that it was of great practical value. Astrology was an important driver of astronomy in many cultures.