Friday the 13th · JPL DE421 · UTC
Friday the 13th,
by the sky.
The next Friday the 13th is August 13, 2027. No planet stations, reaches cazimi or opposition, or crosses a shadow boundary that day. 3 planets are retrograde: Saturn, Neptune, and Pluto.
Friday the 13th is a quirk of the calendar, not of the sky: the planets do not know what day of the week it is. So here is what they actually do on each one, from NASA JPL's DE421 ephemeris, to the minute in UTC. No superstition, no horoscope.
The 6 Friday the 13ths to 2030
| Date | Retrograde | Events (UTC) | Moon | Next station |
|---|---|---|---|---|
| Saturn, Neptune, and Pluto Shadow: Uranus |
— | Waxing gibbous, 88% lit | Uranus: Station retrograde, Sep 15, 2027 09:09 UTC | |
| Saturn, Uranus, Neptune, and Pluto Shadow: Mercury |
— | Waning crescent, 28% lit | Pluto: Station direct, Oct 19, 2028 03:42 UTC | |
| Mars and Jupiter Shadow: Uranus, Neptune, and Pluto |
— | New moon, 21:40 UTC | Mercury: Station retrograde, May 1, 2029 23:05 UTC | |
| Pluto Shadow: Jupiter, Saturn, Uranus, and Neptune |
— | Waxing crescent, 4% lit | Neptune: Station retrograde, Jul 14, 2029 02:10 UTC | |
| Neptune and Pluto Shadow: Mercury, Jupiter, Saturn, and Uranus |
— | Full moon, 97% lit | Saturn: Station retrograde, Sep 20, 2030 21:30 UTC | |
| Mercury, Saturn, Uranus, and Neptune Shadow: Pluto |
— | Waning gibbous, 89% lit | Neptune: Station direct, Dec 21, 2030 20:40 UTC |
Days are UTC dates. "Retrograde" lists every planet that is retrograde at any minute of that UTC day; "shadow" the planets in their pre- or post-shadow. Moon: a principal phase that falls that day, otherwise the phase and lit fraction at 12:00 UTC. Put every station in your calendar · Which planets are retrograde today.
Why there is no Friday the 13th in astronomy
A week of seven days and a month of 28 to 31 days are human counts, so the 13th lands on a Friday one to three times a year, on a pattern that repeats every 400 years. Planets move on their own clocks: Mercury stations about every 58 days, the Moon goes from new to new in 29.5. When a Friday the 13th coincides with a station or a full Moon, it is chance. That is why we list the coincidences instead of predictions. How the times are computed.
Questions
When is the next Friday the 13th?
August 13, 2027, then October 13, 2028. The next planetary station after it: Uranus, station retrograde, September 15, 2027 at 09:09 UTC.
Is Mercury retrograde on Friday the 13th?
Of the Friday the 13ths to 2030, Mercury is retrograde on December 13, 2030. The next Mercury retrograde starts February 9, 2027 at 17:36 UTC and ends March 3, 2027 at 12:32 UTC.
Does anything happen in the sky on Friday the 13th?
Nothing caused by the date: it is a calendar coincidence. The real events are stations, cazimi and oppositions, which fall on any weekday; the next one after August 13, 2027 is Uranus, station retrograde, September 15, 2027 at 09:09 UTC.