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Many Happy Returns

A birthday follows a successful trip around the Sun. That is, if the place you're celebrating happens to revolve around the Sun.

ship's date—

When did you come aboard?

Positions computed from Keplerian orbital elements (JPL approximate ephemerides, J2000 + secular rates; best 1800–2050). Radial distances are log-scaled so Mercury and Pluto can share one map. Angles and dates are real. Earth's returns are counted by the calendar, on your birthday (29 February birthdays fall on 28 February in other years); the other planets' by the mean orbital period in those same elements. The model ignores the planets' pull on each other, so outer-planet return dates can be off by days to weeks. † Pluto was demoted to dwarf planet in 2006; it kept its clock.