The temporal schema for GML 3.1 provides constructs for handling time-varying spatial data. This schema reflects a partial implementation of the model described in ISO 19108:2002. Copyright (c) 2002-2005 OGC, All Rights Reserved. For conditions, see OGC Software Notice http://www.opengeospatial.org/about/?page=ipr This abstract element acts as the head of the substitution group for temporal primitives and complexes. The abstract supertype for temporal objects. This abstract element acts as the head of the substitution group for temporal primitives. The abstract supertype for temporal primitives. This abstract element acts as the head of the substitution group for temporal complexes. Temporal complex is an aggregation of temporal primitives as its components, represents a temporal geometric complex and a temporal topology complex. N.B. Temporal geometric complex is not defined in this schema. The abstract supertype for temporal complexes. This abstract element acts as the head of the substitution group for temporal geometric primitives. The abstract supertype for temporal geometric primitives. A temporal geometry must be associated with a temporal reference system via URI. The Gregorian calendar with UTC is the default reference system, following ISO 8601. Other reference systems in common use include the GPS calendar and the Julian calendar. Omit back-pointers begunBy, endedBy. This model group is provided as an alternative to the abstract susbstitutionGroup head _timeLength. ISO 19136 comment 411 This element is an instance of the primitive xsd:duration simple type to enable use of the ISO 8601 syntax for temporal length (e.g. P5DT4H30M). It is a valid subtype of TimeDurationType according to section 3.14.6, rule 2.2.4 in XML Schema, Part 1. This element is a valid subtype of TimeDurationType according to section 3.14.6, rule 2.2.4 in XML Schema, Part 1. This type extends the built-in xsd:decimal simple type to allow floating-point values for temporal length. According to the ISO 11404 model you have to use positiveInteger together with appropriate values for radix and factor. The resolution of the time interval is to one radix ^(-factor) of the specified time unit (e.g. unit="second", radix="10", factor="3" specifies a resolution of milliseconds). It is a subtype of TimeDurationType. Standard units for measuring time intervals (see ISO 31-1). Direct representation of a temporal position Direct representation of a temporal position. Indeterminate time values are also allowed, as described in ISO 19108. The indeterminatePosition attribute can be used alone or it can qualify a specific value for temporal position (e.g. before 2002-12, after 1019624400). For time values that identify position within a calendar, the calendarEraName attribute provides the name of the calendar era to which the date is referenced (e.g. the Meiji era of the Japanese calendar). The ISO 19108:2002 hierarchy of subtypes for temporal position are collapsed by defining a union of XML Schema simple types for indicating temporal position relative to a specific reference system. Dates and dateTime may be indicated with varying degrees of precision. dateTime by itself does not allow right-truncation, except for fractions of seconds. When used with non-Gregorian calendars based on years, months, days, the same lexical representation should still be used, with leading zeros added if the year value would otherwise have fewer than four digits. An ordinal position may be referenced via URI identifying the definition of an ordinal era. A time coordinate value is indicated as a decimal (e.g. UNIX time, GPS calendar). Calendar dates may be indicated with varying degrees of precision, using year, year-month, date. When used with non-Gregorian calendars based on years, months, days, the same lexical representation should still be used, with leading zeros added if the year value would otherwise have fewer than four digits. time is used for a position that recurs daily (see clause 5.4.4.2 of ISO 19108:2002). This enumerated data type specifies values for indeterminate positions.