rough data:
| year | # | phase |
|---|---|---|
| 2020 | 27 | New |
| 2021 | 16 | New |
| 2022 | 19 | Full |
| 2023 | 23 | New |
| 2024 | 27 | Full |
| 2025 | 30 | New |
... a lunar month is ABOUT 29.5 days ... a year is ABOUT 365.25 days ... and that ratio is ABOUT 12.4 lunar months/year ... and a calendar month is ABOUT 30.4 days ... and a multi-year rule could crudely be based on:
- remember an anchor Magic Moon phase number, like "23 in 2023"
- odd years are NEW, even years are FULL
- add 3 or 4 every year
- to estimate the lunar phase-day for a month, take the Magic Moon number minus the month number
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