Prehistoric simply means before written records, so the date for the start of the historic period would depend on where in the world you are and when the first written records began.
Sometimes places have a protohistoric period. This refers to a time when we have written records for a people but they are written by outsiders (for example Britons had no written records of their own when the Romans arrived, but we know about them from things the Romans wrote about them).
Scientists differentiate between the Paleolithic, Mesolithic, and Neolithic periods by examining changes in tools and technology, such as the shift from simple stone tools in the Paleolithic to more complex tools in the Mesolithic and Neolithic. They also look at changes in human settlement patterns, such as the transition from nomadic hunting and gathering to settled farming communities in the Neolithic. Additionally, changes in art and symbolic expression, such as cave paintings, can also help to distinguish between these periods.
Scientists do not always use a 120 year range when radiocarbon dating an artifact. Calibrated radiocarbon ages are often expressed as below 2670 (± 120) where 2670 refers to the age of the sample and the 120 after the symbol indicates that this age may be older or younger than the given age by 120 years. This varying level of precision comes in because the calibration curves used to turn radiocarbon ages into calender dates are not perfectly smooth, and it may be that for some preiods a radiocarbon age may be equivilent to serveal calender dates. This margin of error varies depending on the age of the sample and for some periods will be significantly less (maybe only a decade or so) and for some periods will be significantly more (for example during the early Iron age, 800 - 400BC where radiocarbon dating can offer no greater precision than several hundered years.
By studying absolute chronology, historians can ascertain the exact dates and time periods of historical events. This enables them to establish a clear timeline of events and understand the sequence in which they occurred. It also helps historians correlate different events happening simultaneously in different regions and analyze the impact of one event on another.
The Bedouin dried some of the dates they found in order to prolong their shelf life and make them easier to transport and store. Drying the dates removes the moisture content, preventing bacterial growth and inhibiting spoilage. This allows the Bedouin to save the dates for a longer period of time and consume them later.
The word for the study of dates and the sequence of events in time is "chronology."
Prehistoric - 2010 was released on: USA: 28 February 2010
Prehistoric Disasters - 2009 was released on: USA: March 2009
Prehistoric Perils - 1951 was released on: USA: 28 December 1951
Jungle of Prehistoric Animals - 1924 was released on: USA: 28 March 1924
Prehistoric Super Salesman - 1969 was released on: USA: 1 September 1969
An Historic Feat - 1900 was released on: USA: May 1900
Prehistoric - 2010 Dallas 1-3 was released on: USA: 24 November 2010
Boo - 2003 Bedroom Prehistoric Land was released on: USA: 7 February 2007
Sackboy's Prehistoric Moves - 2010 VG was released on: USA: 7 December 2010
The Croods Prehistoric Party - 2013 VG was released on: USA: 19 March 2013
Svengoolie - 1995 Women of the Prehistoric Planet was released on: USA: 18 May 1996
Svengoolie - 1995 Monster from a Prehistoric Planet was released on: USA: 8 July 2006