An era is not a defined number of years. Rather, it is a period of time marked by certain characteristics, such as historical events. In geology, an era is composed of periods.Know More
According to the Encyclopedia Britannica, geological eras encompass millions of years. The main eras, according to geologists, are the Paleozoic Era, the Mesozoic Era and the Cenozoic Era. The Paleozoic Era, for instance, was approximately 291 million years long, while the Mesozoic Era lasted about 185.5 million years. The Cenozoic Era has been about 65.5 million years long so far as it runs to the present day.
Historical eras are defined by certain historical events or a distinctive period of time. For instance, the Elizabethan era is defined by the reign of Queen Elizabeth the First, who was the Queen of England from 1558 to 1603.Learn more about Time & Calendars
Generally, the eras used to describe the modern Earth are the Quaternary geological era and the Cenozoic evolutionary era. In the future, there may also be a historical era that the current time period, the 21st century, will belong to.Full Answer >
The days start getting longer every year after the winter solstice, which falls on the first day of winter, the shortest day of the year. The first day of winter is typically December 21 or 22 in the Northern Hemisphere.Full Answer >
Some holidays and events that happen in September include Labor Day, the start of school in many states, memorials for September 11 and more. September also signals the beginning of the fall season, with temperatures cooling in the northern portion of the United States.Full Answer >
The date that clocks are turned back for Daylight Savings Time changes each year. In 2015, the day to turn the clocks back is Nov. 1. The day to turn the clocks forward an hour is be March 8, 2015.Full Answer >