The Void Calendar is a screen where you can check the Moon’s void time (void-of-course), lunar phases, ingresses, retrogrades, and aspects in a familiar monthly calendar format. It has nothing to do with an individual’s natal chart — it overlays Earth-wide astronomical phenomena onto a calendar.
Prerequisite: This screen operates independently of birth data. When you open the page, the calendar for the current year and month is displayed automatically. If you change the year or month, press the “Show” button (there are no previous/next month arrow buttons).
Contents of this page
1. Screen layout and how to specify the month
There are no previous/next month arrow buttons. Enter the year as a number, select the month from the dropdown, and press the “Show” button to calculate and display that month’s calendar. The calendar uses the familiar Sunday-start monthly format, and each day’s cell stacks “date” → “void band (if applicable)” → “other event labels” in that order. Today’s date is outlined with a border.
2. Year, month, and time zone settings
| Item | Options / Range | Default | Notes |
|---|---|---|---|
| Year | 1800〜2200 | Current year | Applied by pressing “Show” after changing |
| Month | 1〜12 | Current month | Applied by pressing “Show” after changing |
| Time zone | JST(UTC+9) and 7 other major zones | Saved value from the settings screen (JST if none) | Selecting it immediately updates the calendar’s time display |
This screen has no field for specifying a location (latitude/longitude). Void times, lunar phases, ingresses, retrogrades, and aspects are all Earth-wide phenomena that do not depend on location. The time zone setting only switches the display format of the times.
3. How to read void times
The Moon’s void time is displayed as a purple band within the cell. The band contains the time range and the sign symbol.
| Situation | Display |
|---|---|
| Starts and ends within the same day | “Start time–End time” |
| Continues from the previous day and ends today | “→–End time” |
| Starts today and continues into the following day or later | “Start time–→” |
| Neither starts nor ends today, but continues throughout | “All-day void” (background is a slightly darker purple) |
If the void moves into the next sign within the same day, “origin sign symbol→destination sign symbol” is displayed; otherwise, only the origin sign’s symbol is shown. Hovering over the band shows a tooltip with the origin/destination sign names, the void’s start/end times, and details of the last aspect formed.
4. Labels for lunar phases, ingresses, retrogrades, and aspects
Events other than voids are displayed as small colored labels stacked in the cell (in chronological order if there are multiple in a day).
| Type | Displayed content | Color |
|---|---|---|
| Lunar phase | Phase symbol (● New Moon / ◐ First Quarter / ○ Full Moon / ◑ Last Quarter) + time + phase name | Yellow |
| Ingress | Planet symbol + “→” + destination sign symbol + time | Green |
| Retrograde/Direct | Planet symbol + “R” (retrograde) or “D” (direct) + time | Retrograde = red, Direct = green |
| Aspect | Planet 1 symbol + aspect symbol + Planet 2 symbol + time | Gray-blue |
The Moon’s sign changes are not shown in this event area. Since the Moon’s ingress is already indicated by the void band display (origin→destination sign symbols), the ingress labels only apply to bodies other than the Moon.
Hovering over a label shows a tooltip with details such as the planet name, destination sign name, and time.
5. Switching layer display
Using the checkboxes in the control row (all ON by default), you can individually turn each layer displayed on the calendar ON/OFF.
| Layer | Covers |
|---|---|
| Void | The Moon’s void time bands |
| Lunar phase | New Moon, First Quarter, Full Moon, Last Quarter |
| Ingress | Sign changes of planets (other than the Moon) |
| Retrograde | Start of retrograde motion / resumption of direct motion for planets |
| Aspect | Aspects formed between planets |
Unchecking a box removes the display immediately, without querying the server again. If you uncheck everything, the calendar shows only the dates.
6. PDF and ICS export
| Button | Action |
|---|---|
| 🖨 PDF (A4) | Opens the browser’s print dialog (A4 landscape). Only the calendar body and legend are printed/saved as PDF, excluding the header and settings area. Even if displayed in dark mode, the display temporarily switches to light mode for printing and reverts afterward. |
| 📅 ICS | Downloads the content of the currently displayed year/month and the layers that are ON as an ICS file that can be imported into calendar apps (file name: “calendar_年_月.ics“). Voids are exported as events spanning from start to end time, while lunar phases, ingresses, retrogrades, and aspects are exported as 5-minute events starting at the time they occur. |
7. Useful specifications to know
- Always shows exactly one month: Unlike the ephemeris table screen, there is no “period: 1/3/6/12 months” option. To view multiple months in sequence, change the year/month and press “Show” again.
- There is no concept of orb: Aspect and void detection only catches the instant when the angle exactly matches (5 types: conjunction, sextile, square, trine, opposition; the counterpart bodies range from the Sun to Pluto).
- Clicking on a cell does nothing: Unlike the ephemeris table screen, this screen has no feature to click through and pass data to the chart screen.
- Settings are retained: Language, theme, and time zone settings are saved in the browser and carried over on your next visit (the year/month always reset to “today”).