Every number in Almanox - the sun events, the verdict, the Milky Way core, the moon times - is computed for one point on Earth. Locations is where you choose that point: your GPS, a city by name, or exact coordinates, saved so you can flip between the spots you actually shoot.
Open Locations by tapping the place name at the top of Today or Tonight.
The location name sits at the top of both the Today and Tonight screens. Tap it and the Locations screen opens, listing every place you have saved with the active one marked. Switching is one tap - pick a tile and the whole app recomputes for that spot, and Almanox remembers your choice for next time.
There are three ways to set where you are planning for:

Your list is yours to curate - with one guard rail so you are never left with nowhere.
Free includes three saved locations, which covers home, a nearby dark site and a travel spot. Pro lifts the cap to unlimited, for anyone who plans across many places.
City search and reverse-geocoding need a connection; once a place is saved, all of its sun, moon and star-chart readings compute on-device with no signal.
Almanox is a one-time $12.99 purchase - no subscription, no ads, no account. Save your spots and the whole almanac follows you to each one.