Planetary Hour Calculator

How does the tool find the planetary hour?

It starts from the ruler of the weekday and steps through the Chaldean order, Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon, one planet per hour. The first hour of the day, 06:00 to 06:59, belongs to the day ruler, so on Sunday it is the Sun, then Venus, Mercury, Moon and onward, wrapping round after seven steps. The result for your hour is the planet reached after that many steps.

Does it use real sunrise and sunset?

No. Traditional planetary hours start at local sunrise, but this tool has no location or date input, so it uses a fixed 06:00 start. Clock hours from 00:00 to 05:59 are counted as the end of the previous weekday’s cycle. The result will be wrong whenever your real sunrise is far from 06:00.

Are the hours all 60 minutes long?

In this tool, yes. Classical planetary hours divide the daylight and the night into twelve parts each, so their length changes with the season and latitude. The calculator uses 24 equal clock hours, and a fractional hour such as 9.5 is rounded down to 9.

Why does the order run Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon?

It is the traditional ranking of the seven classical planets by how slowly they appear to move, slowest first. Stepping through it for 24 hours moves three places along, which is why the ruler of each next day is three steps further on. That produces the familiar weekday sequence Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn.

What are the “traditional qualities” and “associated activities” lines?

Fixed text stored in the tool for each of the seven planets. They are traditional associations from the planetary-hour system, written as short lists. They are not instructions, forecasts or recommendations, and they do not change with your hour apart from which planet is selected.

What does the “Day ruler” row show before 6 a.m.?

The ruler of the astrological day that is still running, and the row says which weekday that is. For example Monday at 03:00 shows the Sun with the note that Sunday’s cycle began at 06:00 the day before, because the Moon’s day only starts at 06:00 on Monday.

How does it handle blank or out-of-range hours?

An hour of 0 is accepted as midnight, and that is also what an emptied box becomes, so it is not replaced by the starting hour of 9. Numbers below 0 become 0 and numbers above 23 become 23. Time zones and daylight saving are not handled, so enter the clock time exactly as it is on the wall.

Is any of this scientifically validated?

No. Planetary hours belong to traditional astrology and ceremonial practice, and their claims have not been scientifically validated. The tool predicts nothing and offers no advice. It performs a fixed counting rule on the weekday and the hour.