Class

• <DRM Absolute Time>

Superclass

• <DRM Time Point>

Subclass

• None.

Definition

An instance of this DRM class specifies an absolute time (that is, Greenwich Mean Time (GMT), which is not relative to some other point in time).

<DRM Absolute Time> provides

1. a means to specify an absolute time (GMT) for metadata, and
2. a general-purpose mechanism for describing points in absolute (GMT) time.

The time_value field specifies the time value.

Class diagram

Figure 6.1 — DRM_Absolute_Time

Constraints

• Legal time ranges
• Publishable Object

Example(s)

• Consider a SEDRIS transmittal constructed from a historical database, in which the time at which an event happened is recorded as Oct 3 17:56:47 GMT 1994. In the SEDRIS transmittal, this information is specified by an <DRM Absolute Time> instance with time_significance = OCCURRENCE, as follows.

  time_significance	=	OCCURRENCE
  time_value. value.ymd_hms. year	=	1994
  time_value. value.ymd_hms. month	=	OCTOBER
  time_value. value.ymd_hms. day_of_month	=	3
  time_value. value.ymd_hms. hour	=	17
  time_value. value.ymd_hms. minutes	=	56
  time_value. value.ymd_hms. seconds	=	47,0

• Consider a SEDRIS transmittal for which the data provider wishes to represent the date and time when the transmittal was created - in this example, Mar 23 15:18:33 GMT 2003. In this case, the data provider would create an <DRM Absolute Time> instance with time_significance = CREATION_DATE and the other field values set appropriately, as follows.

  time_significance	=	CREATION_DATE
  time_value. configuration	=	DATE_YMD_AND_TIME_HMS
  time_value. value.ymd_hms. year	=	2003
  time_value. value.ymd_hms. month	=	MARCH
  time_value. value.ymd_hms. day_of_month	=	23
  time_value. value.ymd_hms. hour	=	15
  time_value. value.ymd_hms. minutes	=	18
  time_value. value.ymd_hms. seconds	=	33,0

  This <DRM Absolute Time> instance would then be attached as a component of the transmittal’s <DRM Transmittal Root>.

• The date and time of observations.