Period

Period may refer to:

Common uses

• Period (punctuation)
• Era, length or span of time
  • Periodization, classifying particular lengths of time into distinct historiographic or artistic periods
  • List of time periods
  • History by period
• Menstruation, commonly referred to as a "period"

Arts, entertainment, and media

• Period (music), concept in musical composition
• Periodic sentence or rhetorical period, concept in grammar and literary style
• Period drama, dramatic film or television production set in a historical period
• Period (Another American Lie), 1987 album by B.A.L.L.
• Period (Kesha album), 2025
• Period (mixtape), 2018 City Girls mixtape
• Period, novel in Dennis Cooper's George Miles cycle
• Periods., comedy film series

Mathematics

• In a repeating decimal, the length of the repetend
• Period of a function, length or duration after which a function repeats itself
• Period (algebraic geometry), numbers that can be expressed as integrals of algebraic differential forms over algebraically defined domains, forming a ring

Science

• Period (gene), gene in Drosophila involved in regulating circadian rhythm
• Period (periodic table), horizontal row of the periodic table
• "Period-" or "per-iod-", chemical prefix where "per" refers to oxidation state and "iod" refers to iodine
• Unit of time or timeframe
  • Period (geology), subdivision of geologic time
  • Period (physics), the duration of time of one cycle in a repeating event
  • Orbital period, the time needed for one object to complete an orbit around another
  • Rotation period, the time needed for one object to complete a revolution
• Wavelength, the spatial period of a periodic wave
• Sentence (linguistics), especially when discussing complex sentences in Latin syntax

Other uses

• Period (school), block of time allocated for a specific course or other purpose
• Playing period, a division of playing time in games and sport
  • Period (ice hockey)
• Accounting period, often shortened to "period" in business, an accounting timeframe analogous to a month
• Periodt, slang of period used as an interjection

See also

• . (disambiguation)
• Duration (disambiguation)
• Full stop (disambiguation)
• Periodicity (disambiguation)