# 8.5.3.12 IfcTimeSeries

ABSTRACT This definition may not be instantiated

## 8.5.3.12.1 Semantic definition

A time series is a set of a time-stamped data entries. It allows a natural association of data collected over intervals of time. Time series can be regular or irregular. In regular time series data arrive predictably at predefined intervals. In irregular time series some or all time stamps do not follow a repetitive pattern and unpredictable bursts of data may arrive at unspecified points in time.

The modeling of buildings and their performance involves data that are generated and recorded over a period of time. Such data cover a large spectrum, from weather data to schedules of all kinds to status measurements to reporting to everything else that has a time related aspect. Their correct placement in time is essential for their proper understanding and use, and the IfcTimeSeries subtypes provide the appropriate data structures to accommodate these types of data.

## 8.5.3.12.4 Formal representation

ENTITY IfcTimeSeries
ABSTRACT SUPERTYPE OF (ONEOF
(IfcIrregularTimeSeries
,IfcRegularTimeSeries));
Name : IfcLabel;
Description : OPTIONAL IfcText;
StartTime : IfcDateTime;
EndTime : IfcDateTime;
TimeSeriesDataType : IfcTimeSeriesDataTypeEnum;
DataOrigin : IfcDataOriginEnum;
UserDefinedDataOrigin : OPTIONAL IfcLabel;
Unit : OPTIONAL IfcUnit;
INVERSE
HasExternalReference : SET [1:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects;
END_ENTITY;

## 8.5.3.12.5 References

### 8.5.3.12.6 Changelog

#### 8.5.3.12.6.1 IFC4

• attribute EndTime type, Changed from "IfcDateTimeSelect" to "IfcDateTime"
• attribute StartTime type, Changed from "IfcDateTimeSelect" to "IfcDateTime"
• inverse attribute DocumentedBy name, Changed from "DocumentedBy" to "HasExternalReference"
• inverse attribute DocumentedBy type, Changed from "SET OF [0:1] IfcTimeSeriesReferenceRelationship FOR ReferencedTimeSeries" to "SET OF [1:?] IfcExternalReferenceRelationship FOR RelatedResourceObjects"