The Saimei period is a chronological

Chronology

Chronology is the science of arranging events in their order of occurrence in time, such as the use of a timeline or sequence of events. It is also "the determination of the actual temporal sequence of past events".Chronology is part of periodization...

 timeframe during the Asuka period

Asuka period

The , was a period in the history of Japan lasting from 538 to 710 , although its beginning could be said to overlap with the preceding Kofun period...

 of Japanese history. The Saimei period describes a span of years which were considered to have begun in the 1315th year of the Yamato dynasty.

This periodization

Periodization

Periodization is the attempt to categorize or divide time into named blocks. The result is a descriptive abstraction that provides a useful handle on periods of time with relatively stable characteristics...

 is congruent with the reign of Empress Saimei, which is traditionally considered to have been from 655 through 662.

Periodization

The adoption of the Sexegenary cycle calendar (Jikkan Jūnishi) in Japan is attributed to Empress Suiko

Empress Suiko

was the 33rd emperor of Japan, according to the traditional order of succession.Suiko's reign spanned the years from 593 until her death in 628....

 in 604; and this Chinese calendar continued in use throughout the Saimei period.

In 645, the system of was introduced. However, after the reign of Emperor Kotoku

Emperor Kotoku

was the 36th emperor of Japan, according to the traditional order of succession.The years of his reign lasted from 645 through 654.-Traditional narrative:Before Kōtoku ascension to the Chrysanthemum Throne, his personal name was or...

, this method of segmenting was temporarily abandoned or allowed to lapse. This interval continued during the Saimei period.

Neither Empress Saimei's reign nor the Saimei periodization are included in the list of nengō for this explicit duration

Duration

In music duration is an amount of time or a particular time interval. A duration is a property of a note that becomes one of the bases of rhythm.A tone may be sustained for varying lengths of time...

 of time

Time

Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....

, which comes after Hakuchi

Hakuchi (era)

was a after the Taika era and before Shuchō. This period spanned the years from February 650 through December 654. The reigning emperor was .-Change of era:...

 and before Suchō

Sucho

Gedalia Suchowolski is an Israeli painter and sculptor known by his nickname Sucho.-Biography:Gedalia Suchowolski was born in Białystok, Poland...

.

In the post-Taika or pre-Taihō chronology, the first year of Empress Saimei's reign (斉明天皇元年 or 斉明天皇1年) is also construed as the first year of the Saimei period (斉明1年).

Non-nengō period

Non-nengō periods in the pre-Taihō calendar were published in 1880 by William Bramsen. These were refined in 1952 by Paul Tuschihashi

Paul Tuschihashi

, S.J. was a Japanese Roman Catholic priest, mathematician, astronomer, Sinologist, lexicographer, academic and administrator. Father Paul is known for having developed extensive tables for converting traditional Japanese era dates into Gregorian calendar equivalents — compare, e.g., which...

 in Japanese Chronological Tables from 601 to 1872.

The pre-Tahiō calendar included two non-nengō gaps or interval

Interval

Interval may refer to:* Interval , a range of numbers * Interval measurements or interval variables in statistics is a level of measurement...

s in the chronological series:

• Taika
  Taika (era)
  was a during the reign of Kōtoku. The Taika era immediately preceded the Hakuchi era. This period spanned the years from August 645 through February 650.-Change of era:...
  
  , August 645–February 650.
• Hakuchi
  Hakuchi (era)
  was a after the Taika era and before Shuchō. This period spanned the years from February 650 through December 654. The reigning emperor was .-Change of era:...
  
  , February 650–December 654.
  • Non-nengō dating systems
• Shuchō
  Shucho
  , alternatively read as Suchō or Akamitori, was a after a gap following Hakuchi and before another gap lasting until Taihō . This Shuchō period briefly spanned a period of mere months, June through September of 686...
  
  , July–September 686.
  • Non-nengō dating systems
• Taihō
  Taiho (era)
  was a after a late 7th century interruption in the sequence of nengō after Shuchō and before Keiun. This period spanned the years from March 701 through May 704. The reigning emperor was .-Change of era:...
  
  , March 701–May 704.

Nengō were not promulgated (or were allowed to lapse) during the gap years between Hakuchi and Shuchō, and in another gap between Shuchō and Taihō.

Concurrent Chronologies
Non-nengō periods	Nengō eras Japanese era name The Japanese era calendar scheme is a common calendar scheme used in Japan, which identifies a year by the combination of the and the year number within the era...	Shinengō	Yamato dynasty duration Imperial House of Japan The , also referred to as the Imperial Family or the Yamato Dynasty, comprises those members of the extended family of the reigning Emperor of Japan who undertake official and public duties. Under the present Constitution of Japan, the emperor is the symbol of the state and unity of the people...	Western calendar dates Gregorian calendar The Gregorian calendar, also known as the Western calendar, or Christian calendar, is the internationally accepted civil calendar. It was introduced by Pope Gregory XIII, after whom the calendar was named, by a decree signed on 24 February 1582, a papal bull known by its opening words Inter...
	Taika		1305	645
	Hakuchi		1310	650
Saimei's reign			1315	655
Tenji's reign Tenji (period) The Tenji period is a brief span of years during the Asuka period of Japanese history. The Tenji period describes a span of years which were considered to have begun in the 1322nd year of the Yamato dynasty....			1322	662
Kōbun's reign Kobun (period) The Kōbun period is a chronological timeframe during the Asuka period of Japanese history. The Kōbun period describes a span of years which were considered to have begun in the 1332nd year of the Yamato dynasty....		Sujaku	1332	672
Temmu's reign Temmu (period) The Temmu period is a chronological timeframe during the Asuka period of Japanese history. The Temmu period describes a span of years which were considered to have begun in the 1333rd year of the Yamato dynasty....		Hakuhō Hakuhō period The was an unofficial of Emperor Temmu after Hakuchi and before Suchō. The duration of this discrete non-nengō timespan lasted from 673 through 686.The Hakuhō period is more often used as a general term which describe a wider range of years....	1333	673
	Suchō		1346	686
Jitō's reign Jito (period) The Jitō period is a chronological timeframe during the Asuka period of Japanese history. The Jitō period describes a span of years which were considered to have begun in the 1347th year of the Yamato dynasty....			1347	687
		Taika	1350	695
Mommu's reign Mommu (period) The Mommu period is a chronological timeframe during the Asuka period of Japanese history. The Mommu period describes a span of years which were considered to have begun in the 1357th year of the Yamato dynasty....			1357	697
	Taihō		1361	701

Events of the Saimei period

• 654 (Hakuchi 4): Emperor Kōtoku, in the 10th year of his reign (孝徳天皇10年), dies at age 59; and his nephew and heir declines the succession (senso). Shortly thereafter, Empress Saimei formally accedes to the throne (sokui).
• 655 (Saimei 1) or "the 1st year of Saimei's reign (斉明天皇元年: A new period is marked by the beginning of the reign of Empress Saimei, but the end of the previous nengō in Hakuchi 6 did not presage the commencement of a new nengō. This dating system was allowed to lapse during Saimei's reign.
• 661 (Saimei 7, 7th month): Empress Saimei, in the 7th year of her reign (斉明天皇7年), designated her son as her heir; and modern scholars construe this as meaning that this son would have received the succession (senso) after her death or abdication. Shortly after she did die at age 68, Emperor Tenji could be said to have acceded to the throne (sokui).

External links

• National Diet Library, "The Japanese Calendar" -- historical overview plus illustrative images from library's collection

Saimei period	1st	2nd	3rd	4th	5th	6th	7th	8th
Gregorian Gregorian calendar The Gregorian calendar, also known as the Western calendar, or Christian calendar, is the internationally accepted civil calendar. It was introduced by Pope Gregory XIII, after whom the calendar was named, by a decree signed on 24 February 1582, a papal bull known by its opening words Inter...	655 655 Year 655 was a common year starting on Thursday of the Julian calendar. The denomination 655 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Europe :* November 15 – Northumbrian king...	656 656 Year 656 was a leap year starting on Friday of the Julian calendar. The denomination 656 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Asia :* The Battle of Bassorah between Ali and Aisha,...	657 657 Year 657 was a common year starting on Sunday of the Julian calendar. The denomination 657 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Asia :* The Chinese Tang Dynasty under Emperor Gaozong...	658 658 Year 658 was a common year starting on Monday of the Julian calendar. The denomination 658 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Europe :* The Union of Slavic Tribes falls apart after...	659 659 Year 659 was a common year starting on Tuesday of the Julian calendar. The denomination 659 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Europe :* Ealdormen in Mercia rebel against...	660 660 Year 660 was a leap year starting on Wednesday of the Julian calendar. The denomination 660 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Europe :* Slavic principality of Carantania is first...	661 661 Year 661 was a common year starting on Friday of the Julian calendar. The denomination 661 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Europe :* Perctarit and Godepert become co-rulers of...	662 662 Year 662 was a common year starting on Saturday of the Julian calendar. The denomination 662 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.- Europe :* The regent Grimuald usurps the kingship of...