80
Copyright © 2010 Open Geospatial Consortium, Inc. AdditionalParameters
A corresponding simple example XML fragment for an ows:OperationsMetadata is:
OperationsMetadata Operation
name =
GetMap DCP
HTTP Get
xlink:href =
http:ww.lat-lon.detransform? HTTP
DCP Operation
Operation name
= GetCapabilities
DCP HTTP
Get xlink:href
= http:ww.lat-lon.detransform?
HTTP DCP
Operation Constraint
name =ParameterOne
AllowedValues Range
MinimumValue 1
MinimumValue MaximumValue
5 MaximumValue
Range AllowedValues
Meaning Meaning of ParameterOne
Meaning DataType
ows:reference =urn:ogc:def:dataType:OGC:1.1:positiveIntegerPositiveIn
teger DataType
Constraint Constraint
name =ParameterTwo
AnyValue Meaning
Meaning of ParameterTwo Meaning
DataType ows:reference
=urn:ogc:def:dataType:OGC:1.1:stringString DataType
Constraint OperationsMetadata
10.9 Temporal Conventions addressing TimeZone Offset and Service handling
A default time zone of UTC as defined by ISO 8601:2004 and ISO 8601:2000 or Greenwich Mean Time, also referred to as ―Z‖ for Zulu Time, shall be used for all
temporal data passed or returned tofrom OGC Web Services. ISO 8601 accounts for local time by specifying an offset to UTC. When time zone offsets are used in a temporal
element of a client request, the server processing the request shall interpret temporal
information with respect to the client’s requested time zone. When there is no time zone offset expressed in a temporal element, an OGC web service shall assume a UTC zone
also referred to as ―Z‖ or Zulu time. The local time zone of client or server shall not be assumed; it shall either be explicitly stated as an offset or assumed to be UTC.
Web services should allow the client to request a time zone offset to be applied to all temporal data through a parameter passed on operations. The web service shall be able to
Copyright © 2010 Open Geospatial Consortium, Inc.
81 convert and return temporal data values from the time zone of the data to the specified
time offset given in the request. An example implementation of the time zone convention is depicted in Figure 17
. The results provided to the client are in Geneva’s time zone offset. Because the client requested a time zone offset of ―+01‖, the results are not
returned in UTC, or the web s ervice’s local time zone, or database server’s local time
zone. In this example, because the database implementation uses a local time, conversion from local time to UTC is required by the database and to client’s time zone by the
service.
Client
Location: Geneva Offset:
+01 Location: New York
Offset: -05
Location: St. Louis Offset:
-06 UTC time of Client request : 2008-08-15T152746
Example: GetMap of precipitation in United States at 2001-09-01T023000 local Geneva time.
Database
GetMap: 2001-09-01T013000+01 local: 2001-09-01T023000
Perform database query at UTC, regardless of local datetime
local 2001-08-31T0163000
Data is stored in local datetime 2001-08-31T0153000, change
results from local datetime to UTC
Change database results time from UTC to client
’s requested time offset 2001-09-01T013000+01
2001-09-01T013000
Client convert to local time: 2001-09-01T0233000
SELECT … 2001-09-01T013000
Web Map Service
Figure 17 — Time Zone Offset Inter-Zone Web Service Request
11 Operation request and response encoding
11.1 General HTTP rules
