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A time instant is a single, atomic time point in the time domain.
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Various models of time have been proposed in the philosophical and logical literature of time. These view time, among other things, as discrete, dense, or continuous.
Instants in the dense model of time are isomorphic to the rational numbers: between any two instants there is always another. Continuous models of time are isomorphic to the real numbers, i.e., they are dense and also, unlike the rational numbers, without “gaps.”
A discrete time domain is isomorphic to (a possibly bounded subset of) the natural numbers, and a specific instant of such a domain then corresponds to some natural number.
The elements of a discrete time domain are often associated with some fixed duration. For example, a time domain can be used where the time elements are specific seconds. Such time elements are often called chronons. In this way, a discrete time domain can approximate a...
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Recommended Reading
Bettini C, Dyreson CE, Evans WS, Snodgrass RT, Wang XS. A glossary of time granularity concepts. In: Etzion O, Jajodia S, Sripada S, editors. Temporal databases: research and practice, LNCS 1399. Berlin: Springer; 1998. p. 406–13.
Jensen CS, Dyreson CE, editors. A consensus glossary of temporal database concepts – February 1998 version. In: Etzion O, Jajodia S, Sripada S, editors. Temporal databases: research and practice. LNCS 1399. Berlin: Springer; 1998. p. 367–405.
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Jensen, C.S., Snodgrass, R.T. (2016). Time Instant. In: Liu, L., Özsu, M. (eds) Encyclopedia of Database Systems. Springer, New York, NY. https://doi.org/10.1007/978-1-4899-7993-3_1516-2
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DOI: https://doi.org/10.1007/978-1-4899-7993-3_1516-2
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