SunlightGuides
Compare sunlight across the year
Keep your garden model fixed and see how calendar dates, hemispheres and local clock changes affect the result.
Use dates rather than season labels
The comparison shows March 21, June 21, September 21 and December 21 in the selected year. These are convenient calendar samples, not calculated astronomical equinox or solstice instants. June generally brings a higher sun and longer days to northern mid-latitudes, while December does so in southern mid-latitudes. Near the equator the pattern differs.
Keep the same physical model
Compare a single location, point and set of obstacles first. If the tree crown changes between scenarios, you are comparing two assumptions as well as two dates. The planner treats a crown as opaque on every date; it does not grow leaves, prune branches or change transparency automatically.
Read local time carefully
Civil noon is not always solar noon. Longitude within a time zone and daylight saving can shift the clock time of the sun’s highest point. The date belongs to the selected location. The slider follows actual elapsed minutes from local midnight, so a DST transition day may have 23 or 25 hours, and some places have half-hour transitions.
Understand repeated and missing hours
On a fall-back day, the same displayed clock hour can happen twice. The UTC offset identifies which instant is shown and is retained in exported timestamps. On a spring-forward day, some clock times do not occur. The timeline follows real elapsed time rather than inventing the missing interval or counting the repeated hour only once.
Choose dates that matter to your question
Four dates reveal broad changes but do not describe every day. Set a particular date to inspect a planned activity or layout decision. At high latitudes the sun may remain above or below the horizon all day. Those are valid geometric results, not missing data. Weather, terrain and the atmosphere are still outside this model.