What is solunar theory?

Solunar theory, developed by John Alden Knight in 1926, proposes that fish and wildlife are most active during specific periods influenced by the position of the sun and moon. Major periods occur when the moon is directly overhead or underfoot; minor periods occur at moonrise and moonset.

What are major and minor fishing periods?

Major periods last roughly 2 hours and occur when the moon is at its zenith (directly overhead) or nadir (directly underfoot). Minor periods last about 1 hour and coincide with moonrise and moonset. Activity is typically highest during major periods near a new or full moon.

Does moon phase affect fishing?

Many anglers and researchers note that fish tend to feed more actively during new and full moon phases, when tidal forces are strongest. The gravitational pull affects not just ocean tides but also lake and river currents, triggering baitfish movement and feeding behavior.

How accurate are the times shown?

Times are calculated using a standard lunar position algorithm (based on Jean Meeus's Astronomical Algorithms) for your selected date at a generic longitude/latitude offset from UTC. Results are approximate — within 10-15 minutes of precise ephemeris data. For exact local times, cross-reference with a local tide chart.

Why are there no tide heights shown?

Actual tide heights depend on local geography (bay shape, depth, coastline) and require real-time NOAA or local authority data. This tool focuses on the solunar component — moon-phase-driven feeding activity — which applies equally to freshwater and saltwater fishing.

What does the fishing activity score mean?

The score (0-100) combines moon phase strength (new/full = highest) and the number of peak windows in the day. A score above 70 suggests an excellent fishing day; 40-70 is average; below 40 indicates slower activity.

Tide Fishing Planner

Name: Tide Fishing Planner
Availability: InStock
Author: Nham Vu

Pick a date to see the moon phase, solunar major and minor fishing windows, and an overall fishing activity score — no login or API key needed.

Select a Date

Date

Select a date and calculate

Your solunar peak fishing windows will appear here.

Done

Summary

Pick a date to see the moon phase, solunar major and minor fishing windows, and an overall fishing activity score — no login or API key needed.

How it works

The tool calculates the Julian date for your selected calendar date.
A lunar phase algorithm (based on Meeus astronomical algorithms) determines the moon age and phase name.
Lunar transit times (overhead and underfoot) are computed from the moon's hour angle, defining major solunar windows.
Moonrise and moonset times define the two minor solunar windows.
A fishing activity score is derived from moon phase proximity to new/full moon and the quality of daily windows.

Use cases

Plan a freshwater bass fishing trip around peak solunar windows.
Identify which days this month have the highest fishing activity scores.
Check whether a full or new moon coincides with your weekend trip.
Schedule early-morning or late-evening outings during major feeding periods.
Teach new anglers about the solunar theory and lunar fishing calendars.

Frequently Asked Questions

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Last updated: 2026-05-29 · Reviewed by Nham Vu