List of time periods

This is a list of named time periods defined in various fields of study. This list is under construction: the eventual aim is for it to be a compendium of names of eras and epochs in all fields of study To do:\n*periods should have approximate dates added in the format (start - finish)\n*lists should be in chronological order of the start of their period. See\n*Periodization for a discussion of the tendency to try to fit history into non-overlapping periods.\n*List of themed timelines\n*Exponential timeline shows all history on one page in ten lines.

Table of contents

1 Cosmological time periods 2 Geologic time periods 3 Human time periods 3.1 Calendar systems 3.2 Human prehistorical periods 3.3 Human historical periods 3.4 Specialist human periods

Cosmological time periods

The cosmological timescale is the longest imaginable. It covers the entire\nextent of the universe - many billions of years. A short first period is\nmeasured in tiny fractions of seconds, but thereafter most things happen\non the scale of billion years. It is used to consider events noticeable\non a universal scale, such as the formation of matter, stars, and\ngalaxies.

• The Big Bang (13.7 GYA)\n* The Dark Age between recombination and reionization (13.7-13.5 GYA)\n* The Star-forming Era (13.5 GYA - now)

Geologic time periods

The geologic timescale covers the extent of the existence of Earth, from\nabout 4600 million years ago to the present day. It is used to consider\nthe formation and change of the Earth itself, and large-scale changes \nin the planet's inhabitants. Dates are given as Millions of Years Ago (MYA). \n

Eon	Era	Period	Epoch\n
Precambrian (4600-544 MYA)\n	Hadean (4600-3800 MYA)\n
	Archaean (3800-2500 MYA)\n
	Proterozoic (2500-544 MYA)\n
Phanerozoic (544 MYA - now)\n	Paleozoic (544-245 MYA)\n	Cambrian (544-505 MYA)\n
		Ordovician (505-440 MYA)\n
		Silurian (440-410 MYA)\n
		Devonian (410-360 MYA)\n
		Carboniferous (360-286 MYA)	Mississippian (360-325 MYA)\n
			Pennsylvanian (325-286 MYA)\n
		Permian (286-245 MYA)\n
	Mesozoic (245-65 MYA)\n	Triassic (245-208 MYA)\n
		Jurassic (208-146 MYA)\n
		Cretaceous (146-65 MYA)\n
	Cenozoic (65 MYA - now)\n	Tertiary (65-1.8 MYA)\n	Paleocene (65-54 MYA)\n
			Eocene (54-38 MYA)\n
			Oligocene (38-23 MYA)\n
			Miocene (23-5 MYA)\n
			Pliocene (5-1.8 MYA)\n
		Quaternary (1.8 MYA - now)\n	Pleistocene (1.8-0.01 MYA)\n
			Holocene (0.01 MYA - now)\n

\nThe Paleocene, the Eocene, and the Oligocene are also collectively known as the Paleogene. The Miocene and the Pliocene\nare also collectively known as the Neogene. These names differ across different countries; in particular, the division\nof the Carboniferous period into Mississippian and Pennsylvanian\nis purely a North American distinction.

Human time periods

The "human" timescale covers the time that humans have existed, usually\ntaken to be from about 250,000 years ago - when Homo Sapiens began to develop.\nIt is broadly divided into prehistorical (before history began to be recorded)\nand historical periods (when written records began to be kept).

Calendar systems

• Common Era

Human prehistorical periods

Human prehistory is usually divided by stages in development. However, different\nparts of the world entered these developmental stages at different times, so\nit is impossible to put firm dates on these periods.

• the stone age - up to about 2500 BC\n** Palaeolithic (Old stone age)\n** Mesolithic (Middle stone age)\n** Neolithic (New stone age)\n* the bronze age - up to about 750 BC\n* the iron age - up to the historical periods

Human historical periods

\n*Antiquity (Ancient Greece, c:a 1000 BC-, see Timeline of Ancient Greece)\n*Pax Romana (Roman Empire, 96 - 180)\n*Period of the Three Kingdoms (China, 220 - 280)\n*Middle ages (Europe, 5th century - 14th century)\n*Nara period (Japan, 709 - 795\n*Period of Five Dynasties and Ten Kingdoms (China, 907 - 960)\n*Sengoku period (Japan, 1478 - 1605)\n*The Renaissance (Europe, 14th century - 16th century)\n*Elizabethan period (United Kingdom, 1558 - 1603)

• Napoleonic Era, 1799-1815\n*Victorian era (United Kingdom, 1837 - 1901)\n*Edwardian period (United Kingdom, 1901 - 1910)\n*Meiji era (Japan, 1868 - 1912)\n*Cold War (United States and Russia, as well as Earth, 1945-1989)\n*Post-communist period (Russia, after 1991)

Specialist human periods

There are many fields which have their own associated historical periods.\nThese include: Not yet in any particular order

• Climate\n**Medieval climate optimum\n**Little Ice Age\n**Global warming period\n*Music\n**Renaissance\n**Baroque\n**Classical\n**Romantic\n**Modern\n*Architecture - see also: architectural style\n**Gothic\n**Baroque