Model scope and corrections — read first

This is an idealized geographic-time model: 15° of longitude corresponds to one hour of local solar time, but civil time zones need not be 15° wide or differ by exactly one hour; some use 30- or 45-minute offsets. The International Date Line bends around political boundaries rather than following 180° throughout. In a rotating frame, the Coriolis effect deflects motion to the right in the Northern Hemisphere and left in the Southern Hemisphere, but it does not generally determine which riverbank erodes. Polar-circle boundaries and polar-day/night durations are geometric approximations; atmospheric refraction and definitions of sunrise and sunset can change observed results.

Geographic Time · Module 01

Earth Rotation

Local time · Time zones · Circle of illumination · Rotation direction

Key concepts

Rotation speed

Simulation speed multiplier 30×

View

Visualization layers

Sunlight rays Circle of illumination Latitude–longitude grid Time zone boundaries Local time labels Rotation direction Tropics North and South Poles Cloud layer Glow

Reference cities

Date (subsolar latitude)

March equinox 3/21 +0.0°

Concept explanations

geo · time · spatial

Sunlight rays

Equator

Circle of illumination

Latitude–longitude grid

Left-drag to rotate · Scroll to zoom · Right-drag to pan

Live data

UTC time00:00:00

Subsolar longitude0.0°

Subsolar latitude+0.0°

Rotation directionWest to east

Coriolis force (Northern Hemisphere)Deflects to the right

Reference cities