As an expert in the field of astronomy and timekeeping, I can provide you with a detailed explanation of what constitutes night time and how it is determined. Night time, also referred to as nighttime, is a period of darkness that occurs when the Sun is below the horizon. This period is marked by the absence of direct sunlight and is characterized by the appearance of the Moon and stars in the sky.

The transition from day to night is not instantaneous; it occurs gradually as the Earth rotates on its axis. The process begins with the sunset, which is the moment when the Sun's upper edge disappears below the horizon. The time of sunset can vary depending on your geographical location and the time of the year. For instance, during the summer months, the days are longer, and the nights are shorter, while during the winter, the opposite is true.

Once the Sun has set, twilight begins. There are three types of twilight: civil, nautical, and astronomical. Civil twilight occurs when the Sun is 6 degrees below the horizon, nautical twilight occurs when it is 12 degrees below, and astronomical twilight occurs when the Sun is 18 degrees below the horizon. Each type of twilight has its own significance for different activities and observations.

As twilight deepens, we enter the period of night time proper. This is when the sky becomes fully dark, and the stars and planets become visible. The duration of night time can also vary depending on your location and the time of the year. In polar regions, for example, there can be periods of continuous daylight or darkness known as the Midnight Sun or Polar Night, respectively.

The end of night time is marked by the sunrise, which is the moment when the upper edge of the Sun becomes visible above the horizon. Similar to sunset, the time of sunrise can also change throughout the year.

It's important to note that the concept of night time is not only astronomical but also cultural and legal. Different societies may have different definitions of night time based on their customs and practices. For example, some cultures may consider night time to begin when it is sufficiently dark for the stars to be visible, while others may use a specific time, such as 9 PM or 10 PM, as the start of the night.

In legal terms, night time can be defined for various purposes, such as regulating the use of lights on vehicles or determining when certain activities are permissible. These definitions can also vary from one jurisdiction to another.

In conclusion, night time is a complex and multifaceted concept that is influenced by astronomical, geographical, cultural, and legal factors. It is a period of rest and rejuvenation for many living organisms and a time for observation and contemplation for those who appreciate the beauty of the night sky.

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Noon is at 12:00 PM. Afternoon is from 12:01 PM to around 5:00 PM. Evening is from 5:01 PM to 8 PM, or around sunset. Night is from sunset to sunrise, so from 8:01 PM until 5:59 AM.read more >>