TY - JOUR A1 - Benzler, Justus A1 - Clark, Samuel J. T1 - Toward a Unified Timestamp with explicit precision Y1 - 2005/03/30 JF - Demographic Research JO - Demographic Research SN - 1435-9871 SP - 107 EP - 140 DO - 10.4054/DemRes.2005.12.6 VL - 12 IS - 6 UR - https://www.demographic-research.org/volumes/vol12/6/ L1 - https://www.demographic-research.org/volumes/vol12/6/12-6.pdf L2 - https://www.demographic-research.org/volumes/vol12/6/12-6.pdf N2 - Demographic and health surveillance (DS) systems monitor and document individual- and group-level processes in well-defined populations over long periods of time. The resulting data are complex and inherently temporal. Established methods of storing and manipulating temporal data are unable to adequately address the challenges posed by these data. Building on existing standards, a temporal framework and notation are presented that are able to faithfully record all of the time-related information (or partial lack thereof) produced by surveillance systems. The Unified Timestamp isolates all of the inherent complexity of temporal data into a single data type and provides the foundation on which a Unified Timestamp class can be built. The Unified Timestamp accommodates both point- and interval-based time measures with arbitrary precision, including temporal sets. Arbitrary granularities and calendars are supported, and the Unified Timestamp is hierarchically organized, allowing it to represent an unlimited array of temporal entities. ER -