How Cazimi
times Mercury.

Cazimi times five moments in each Mercury retrograde cycle, to the minute, in UTC: pre-shadow, station retrograde, cazimi, station direct, and the end of post-shadow.

Station

A station is the minute Mercury's apparent geocentric ecliptic speed changes sign. Seen from Earth, Mercury's ecliptic longitude usually increases. Around each inferior conjunction, Earth's own motion makes that longitude slow, stop, and decrease for about three weeks. The station retrograde is the minute the speed turns negative. The station direct is the minute it turns positive again. For example, Mercury stations retrograde on October 24, 2026 at 07:13 UTC and direct on November 13, 2026 at 15:54 UTC.

Cazimi

Cazimi is the inferior conjunction: the minute Mercury's apparent ecliptic longitude equals the Sun's, with Mercury between Earth and the Sun. It always falls inside the retrograde. The traditional cazimi window is 17 arcminutes (17′) of the Sun. Where that window has been measured, the page shows it, for example 07:38 to 14:25 UTC on March 7, 2026. Elsewhere only the exact minute is given.

Opposition

Cazimi applies only to Mercury and Venus, the planets that can pass between Earth and the Sun. The outer planets, from Mars out to Pluto, never do. In the middle of their retrogrades they reach opposition instead: the minute their apparent geocentric ecliptic longitude is 180° from the Sun's, when they rise at sunset and are up all night. Retrograde planets today.

Shadow

Mercury crosses the degrees of each retrograde three times: forward, backward, and forward again. Pre-shadow starts when Mercury, still direct, reaches the degree where it will later station direct. Post-shadow ends when, after the direct station, Mercury passes the degree of the retrograde station.

Source

The JPL DE421 ephemeris, as noted in the Cazimi iOS engine. The website, the JSON files, and the iPhone app use the same minutes for Mercury; Venus and the outer planets, from Mars out to Pluto, come from the same ephemeris.

Precision

Every time is rounded to the minute and written in UTC. Pages convert times to your clock in the browser. Signs are 30° sections of the ecliptic counted from the March equinox point. Degrees, in degrees and arcminutes, appear only where they have been published. When a degree is missing, the page leaves it blank rather than estimating it. Pages are rebuilt every day at 00:05 UTC, and each answer covers that whole UTC day.

Astronomy, not a horoscope

These are timing facts about apparent motion. Cazimi does not read birth charts or predict events. The daily notes in the app are practical prompts, not forecasts.

Data

The same facts are published as static JSON, open to any origin: /v1/mercury/today.json, /v1/mercury/next.json, /v1/mercury/cycles.json, /v1/planets/today.json for all eight planets, and one Mercury file per year such as /v1/mercury/cycles/2026.json. Plain-text summaries for assistants: llms.txt and llms-full.txt.

Every cycle per planet: mercury, venus, mars, jupiter, saturn, uranus, neptune, pluto. Every Mercury retrograde from 1900 to 2050: /v1/mercury/cycles-1900-2050.json. No key and no sign-up. AI assistants can call the same data through a read-only MCP server at https://cazimi.live/api/mcp (Streamable HTTP, eight tools, no sign-in), listed in the official MCP Registry as live.cazimi/retrogrades. If you publish these times, please link to cazimi.live.

Embed

Paste one line where the badge should appear. It shows whether Mercury is retrograde, links to the daily answer, and reads /v1/mercury/today.json.

<script src="https://cazimi.live/badge.js" async></script>

Preview:

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