Start with the header
A date by itself is incomplete. One table may sample positions at 00:00 UTC and another at 12:00 UTC; the Moon can move several degrees between those times. Check whether positions are geocentric or topocentric, tropical or sidereal, and apparent or geometric. A chart calculated for a recorded local birth time should use that instant rather than a nearby archive row.
Convert sign and degree
The zodiac signs occupy consecutive thirty-degree ranges. Aries begins at 0° ecliptic longitude, Taurus at 30°, and Cancer at 90°. A position of 15° Taurus is 45° longitude; 8° Cancer is 98°. A position just below 30° and one just above 30° may be close in the sky even though their sign names differ. For work near a sign boundary, keep minutes of arc and the exact time instead of relying on rounded display degrees.
Follow motion across rows
Compare a planet's longitude on successive days to see its apparent movement. When a sequence approaches 360° and returns to 0°, unwrap the values mentally or with a plot; that is a zodiac cycle boundary, not an abrupt jump across the sky. A decreasing longitude over several rows can indicate retrograde motion, but a station should be timed with a dedicated event calculation. The daily archive is a sampling tool, while the sky calendar solves selected event times more precisely.
Use the right table for the question
A monthly ephemeris is useful for finding broad periods, checking a claimed position, or choosing a smaller interval for investigation. It does not by itself calculate a person's houses, Ascendant, or local horizon. Those require a place and usually an accurate time. CSV export helps compare records or graph motion, but retain the source convention and date column when reusing the data. If two tables disagree, first align time standard, zodiac, coordinate origin, and rounding before judging the calculations.
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Updated 20 September 2026