Encyclopedia of Database Systems

Living Edition
| Editors: Ling Liu, M. Tamer Özsu

Absolute Time

  • Christian S. JensenEmail author
  • Richard T. Snodgrass
Living reference work entry
DOI: https://doi.org/10.1007/978-1-4899-7993-3_1407-2

Definition

A temporal database contains time-referenced, or timestamped, facts. A time reference in such a database is absolute if its value is independent of the context, including the current time, now.

Key Points

An example is “Mary’s salary was raised on March 30, 2007.” The fact here is that Mary’s salary was raised. The absolute time reference is March 30, 2007, which is a time instant at the granularity of day.

Another example is “Mary’s monthly salary was $15,000 from January 1, 2006 to November 30, 2007.” In this example, the absolute time reference is the time period [January 1, 2006–November 30, 2007].

Absolute time can be contrasted with relative time.

Cross-References

Recommended Reading

  1. 1.
    Bettini C, Dyreson CE, Evans WS, Snodgrass RT, Wang XS. The glossary of time granularity concepts. In: Jajodia S, Etzion O, Sripada S, editors. Temporal databases: research and practice. LNCS, vol. 1399. Berlin: Springer; 1998, p. 406–413.Google Scholar
  2. 2.
    Jensen CS, Dyreson CE, editors. The consensus glossary of temporal database concepts – February 1998 version. In: Etzion O, Jajodia S, Sripada S, editors. Temporal databases: research and practice. LNCS, vol. 1399. Berlin: Springer; 1998. p. 367–405.Google Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  1. 1.Aalborg UniversityAalborg ØstDenmark
  2. 2.University of ArizonaTucsonUSA

Section editors and affiliations

  • Richard T. Snodgrass
    • 1
  • Christian S. Jensen
    • 2
  1. 1.University of ArizonaTucsonUSA
  2. 2.Aalborg UniversityAalborg ØstDenmark