Ephemeris
Ephemerides are tables or calculated data of celestial positions and motions for specified instants. They support astronomy and provide numerical inputs for astrological charts.How it is defined
Before comparing values, check time scale, time zone, reference frame and coordinate type. A UTC table does not necessarily show the same local date as your clock.
How to read it
To check the phenomenon, distinguish the calculated position, its reference time and what an observer can see from their location. These related details answer different questions.
A concrete example
An instant at 00:30 UTC may fall on the previous day in another time zone. Convert the time before consulting the corresponding row.
Explore further
Explore the sources and related concepts. When consulting tables or calendars, look for the date, coordinates and reference frame they use.