Alt text: They're up there with coral islands, lightning, and caterpillars turning into butterflies.
Then please explain how the Hebrew calendar, and all other lunisolar calendars (calendars which follow both the solar year and the lunar cycle) have 12 months most years? https://en.wikipedia.org/wiki/Lunisolar_calendar
"The majority of years have twelve months but every second or third year is an embolismic year, which adds a thirteenth intercalary, embolismic, or leap month."