Methodology

How FeedWindow calculates solunar times

FeedWindow applies a consistent solunar model to astronomical events calculated for the coordinates, calendar date, and time zone of the selected place.

Major periods

Each major period lasts approximately two hours and is centered on a lunar transit: either when the moon is overhead or when it is underfoot on the opposite side of Earth. The displayed window extends approximately one hour before and one hour after the calculated center.

Minor periods

Each minor period lasts approximately one hour and is centered on moonrise or moonset. The displayed window extends approximately 30 minutes before and 30 minutes after the calculated event.

One-to-five day rating

The rating is a compact comparison aid, not a measured probability of success. FeedWindow starts with a phase score: dates nearer a new moon or full moon score higher than dates nearer a quarter moon. It then adds a bonus when a calculated major or minor center falls within one hour of sunrise or sunset. The result is rounded and constrained to a rating from one to five.

Location, date, and time

Place search returns a latitude, longitude, and IANA time-zone identifier through the Open-Meteo Geocoding API. Astronomical events are calculated for those coordinates. FeedWindow converts the results to the selected place’s local civil time, including applicable daylight-saving rules.

Interpretation and limitations

Solunar theory is a traditional planning framework rather than a guarantee that fish or wildlife will be active. FeedWindow does not include weather fronts, barometric pressure, wind, precipitation, tides, water temperature, habitat, species behavior, seasonal patterns, hunting pressure, or local closures. Those factors may be more important on a particular day.

Use the forecast as one input alongside official weather, tide, safety, and regulatory information. Follow all local laws and legal hunting and fishing hours.

Reproducibility

The same location, date, and time zone produce the same forecast. Calculations run locally in the browser; changing the searched place or starting date recalculates the seven-day view.

Method description verified against the deployed calculator: September 5, 2026.