Class Name: Absolute Time Point

Superclass - Time Point

Definition

Used to specify GMT time (i.e. not relative to another date and time).

Primary Page in DRM Diagram:

• 20

Example

1. The date and time when a SEDRIS transmittal was created.
2. The date and time of observations.

FAQs

What is the purpose of this class?

This class provides 1) the means to specify an absolute time (GMT) for the FGDC-compatible metadata and 2) provides a general-purpose mechanism for describing points in absolute (GMT) time. In the first case, the metadata describes the point in time when a high-level SEDRIS object (e.g. Transmittal Root Model, Image, etc.) was created. It allows potential users of a SEDRIS transmittal to evaluate the age of a transmittal, without necessarily having to obtain or examine the transmittal itself.

How can I indicate that the time information in an Absolute Time Point is not dependent on the year?

Setting year = -1 indicates any year. Please note that this means that an actual date of 1 BCE (before common era) cannot be used. This should not be a problem, as it is anticipated that the only time a BCE date will be used will be for astronomical Julian dates.

How can I indicate that the time information in an Absolute Time Point is not dependent on the month?

Setting month = SE_ANY_MONTH indicates any month.

How can I indicate that the time information in an Absolute Time Point is not dependent on the day?

Setting day = -1 indicates any day.

How do I indicate that the time fields hour, minutes, seconds are not applicable, i.e. that I'm specifying only the date?

Setting hour = -1, minutes = -1, and/or seconds = -1, indicate that they are not applicable and can be ignored.

Constraints

• Legal Time Ranges

Component of (one-way)(inherited)

• optionally, some Base Time Constraints Data
• optionally, some Environment Roots
• optionally, a Transmittal Root
• optionally, some Citations
• optionally, some Process

Component of (one-way)

• optionally, some Absolute Time Intervals
• optionally, some Relative Time Intervals
• optionally, some Relative Time Points

Inherited Field Elements

Field Elements

Notes

Fields Notes

time_significance

 Used to indicate the significance of the time information

hour

 Use 24 hour clock for hour. The value must be between
 -1 and 23, where a value of -1 indicates not
 applicable.

minutes

 The value must be between -1 and 59, where a value of
 -1 indicates not applicable.

seconds

 fractions provide higher accuracy if needed, e.g. milliseconds
 -1 indicates not applicable.  This is the only valid negative value.