meiodia

Meio-dia, often written meio-dia in Portuguese, refers to the middle of the day and is commonly associated with 12:00 on a clock. The term derives from the words meio (half) and dia (day), indicating the point halfway through the daylight period.

In timekeeping, meio-dia can denote two related concepts. Civil or local noon is the time in a given time zone when the clock reads 12:00 and the sun is highest in the sky according to the local civil time. Solar noon is the astronomical moment when the Sun crosses the local meridian. Civil noon can differ from solar noon by several minutes due to the equation of time, which accounts for the eccentricity of Earth's orbit and its axial tilt, and also because time zones and daylight saving adjustments may shift clock time relative to solar noon.

Variations in longitude within a time zone mean that some places reach solar noon earlier or later than others, even though they share the same civil meio-dia. Consequently, the moment of solar noon can drift through the year by up to about 15 minutes around the clock noon. In practice, meio-dia is also culturally associated with mealtime in many Portuguese-speaking communities, where lunch is commonly taken near or around noon.

Beyond its role as a time reference, the concept of meio-dia appears in literature and media as a symbolic moment of transition or peak activity in the day, reflecting the universal importance of noon as a daily marker.