What a sunlight estimate can and cannot tell you
Separate sun position, geometric potential and actual direct sunlight.
Three different questions
Sun position tells you where the sun is in the sky at an instant. Potential direct sunlight asks whether it is above the assumed horizon and in front of your opening. Actual sunlight asks whether its rays reach the particular surface after buildings, trees, roofs and other objects block them.
SunSide calculates the first two and automatically loads public Overture building footprints and recorded heights. Open patio mode intersects solar rays with mapped polygon extrusions at a ground-level point. Missing heights remain unknown; no heights are invented from floor counts. Terrain is assumed level, roofs are simplified, and map coverage is limited to a 600 m square half-width. Dataset heights can be estimates and tile geometry is quantized. Trees, overhangs and elevated balconies are unresolved. Balcony/window mode retains facing-direction potential because the opening elevation is unknown. Optional cloud forecasts remain separate from the geometric model. Open patio mode considers one selected point, not the sunny percentage of a whole patio.
What do the angles mean?
Azimuth is the compass bearing clockwise from true north. Altitude is the angle above the horizon, with 90° directly overhead. The sky diagram is a top-down radial plot: center is overhead, edge is horizon. It is not a perspective photograph of your space.
How precise are the times?
Exposure intervals use five-minute bins, classified at each bin’s midpoint. Boundaries are approximate, and very short intervals may be missed. Position at the slider instant is calculated directly. Daylight is defined here as the apparent sun center above the horizon; it is different from a standard sunrise table based on the upper limb.
Local clock time matters
Choose the time zone belonging to the selected coordinates. Manual coordinates and device location do not automatically determine that zone. Daylight-saving changes are applied by the selected IANA zone. Clouds and atmospheric conditions can change actual exposure regardless of geometry.