gml:AbstractTimeSlice 

To describe an event — an action that occurs at an instant or over an interval of time — GML provides the gml:AbtractTimeSlice element. A timeslice encapsulates the time-varying properties of a dynamic feature -- it shall be extended to represent a time stamped projection of a specific feature. The gml:dataSource property describes how the temporal data was acquired.
A gml:AbstractTimeSlice instance is a GML object that encapsulates updates of the dynamic—or volatile—properties that reflect some change event; it thus includes only those feature properties that have actually changed due to some process.
gml:AbstractTimeSlice basically provides a facility for attribute-level time stamping, in contrast to the object-level time stamping of dynamic feature instances. 
The time slice can thus be viewed as event or process-oriented, whereas a snapshot is more state or structure-oriented. A timeslice has richer causality, whereas a snapshot merely portrays the status of the whole.

Element Information

Model

gml:metaDataProperty* , gml:description{0,1} , gml:descriptionReference{0,1} , gml:identifier{0,1} , gml:name* , gml:validTime , gml:dataSource{0,1}
Children: gml:dataSource, gml:description, gml:descriptionReference, gml:identifier, gml:metaDataProperty, gml:name, gml:validTime

Attributes

QName Type Fixed Default Use Inheritable Annotation
gml:id ID required 
The attribute gml:id supports provision of a handle for the XML element representing a GML Object. Its use is mandatory for all GML objects. It is of XML type ID, so is constrained to be unique in the XML document within which it occurs.

Used By

Complex Type gml:HistoryPropertyType

Source 

<element name="AbstractTimeSlice" type="gml:AbstractTimeSliceType" abstract="true" substitutionGroup="gml:AbstractGML">
  <annotation>
    <documentation>To describe an event — an action that occurs at an instant or over an interval of time — GML provides the gml:AbtractTimeSlice element. A timeslice encapsulates the time-varying properties of a dynamic feature -- it shall be extended to represent a time stamped projection of a specific feature. The gml:dataSource property describes how the temporal data was acquired. A gml:AbstractTimeSlice instance is a GML object that encapsulates updates of the dynamic—or volatile—properties that reflect some change event; it thus includes only those feature properties that have actually changed due to some process. gml:AbstractTimeSlice basically provides a facility for attribute-level time stamping, in contrast to the object-level time stamping of dynamic feature instances. The time slice can thus be viewed as event or process-oriented, whereas a snapshot is more state or structure-oriented. A timeslice has richer causality, whereas a snapshot merely portrays the status of the whole.</documentation>
  </annotation>
</element>

Sample