Timeranges

Timeranges are spans of time used to denote the period during which an event occurs or data is observed. A timerange is typically defined by a start time and an end time, expressed as timestamps or ISO 8601 date-time values. In data processing and database queries, timeranges serve as filters to select the portion of data that lies within a given window.

Notation and endpoints: Timeranges are often written with inclusive or exclusive endpoints, for example [start, end), (start, end], or as a simple pair (start, end). The choice of convention affects calculations such as duration and overlap and must be defined for a given application. Timeranges can be bounded, with both ends finite, or unbounded, where one end extends to infinity.

Operations: Common operations include measuring duration, checking whether a time point lies within the range, computing intersection or union of ranges, shifting a range by a duration, and determining overlap between ranges. These operations underpin time-series analysis, windowed computations, and scheduling logic.

Representations: Time values are typically represented as ISO 8601 strings, timestamps, or integer units in seconds or milliseconds. Durations are expressed in units such as seconds, minutes, or hours.

Challenges: Time zone handling, daylight saving time transitions, leap seconds, and ambiguous times can complicate timerange calculations. Defining consistent inclusivity and handling missing data are also important considerations.

Applications: Timeranges are used in database queries, log analysis, financial time series, monitoring dashboards, and event scheduling. See also time interval, time window, and window function.