About Time

Time is the concept of progression and sequence - as we live, we always move through time.

Time is most commonly measured in the following units:

• Year
  The amount of time between New Year's Day of one year, and New Year's Day of the next consecutive year. This period roughly corresponds to the Earth making a full orbit around the sun.
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  This amount of time is not constant - in a leap year, a year contains one extra day.

• Month
  The 12 periods in which a year is divided
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  This amount of time is not constant - the number of days in a month depending on the specific period of a year.

• Week
  The amount of time consisting of 7 days
• Day
  The amount of time consisting of 24 hours, in most cases. This period roughly corresponds to a full rotation around the Earth's axis
• Hours
  The 24 periods in which a day is divided. Generally, hours between 6 AM and 6 PM are bright (daytime) and hours between 6 PM and 6 AM are dark (night time).
• Minutes
  The 60 periods in which an hour is divided
• Seconds
  The 60 periods in which a minute is divided
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  When a leap second is added to or removed from a day, the number of seconds in a minute can temporarily change to 61 or 59.

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Other units for time are also available, however, the aforementioned units are the most commonly used.

About Leap Years

In the Gregorian calendar, every fourth year contains an extra day in the month of February (with exceptions). This extra day accounts for the fact that the Earth's orbit around the sun is not an integer amount of days.

About Timezones

As the Earth is a roughly spherical object, when it rotates on its axis, different parts of the Earth become bright and dark at the same time. In order to account for this, different parts of the world run on different timezones. In most cases, this ensures that daytime and night time are experienced at roughly the same hours at every spot in the world.

About Daylight Savings Time

Daylight Savings Time is a special event that is observed in some timezones - as the Earth is a roughly spherical object, locations closer to the poles of the Earth tend to have more of a deviance between the length of a day and the length of the night. Daylight Savings Time is an event that lasts for roughly half a year in these timezones, and shifts the timezone to adjust the day time so that it starts in the later hours of the morning.