Understanding the different dates¶

The number of different dates is one of the main issues raised during the documentation and consultation phases. Most of the time, this is due to confusion between the two types of dates:

those concerning the documented resource (data, service, etc.);
those concerning the metadata record for this resource.

For your information, Isogeo systematically uses the Gregorian calendar, and dates are stored asISO 8601 timestamps in the UTC time zone.

Resource dates¶

The dates linked to the data are grouped together in the[History] tab (../features/documentation/md_history.md) and are divided into 2 different sections:

Validity period and Update frequency ;
Events.

Automatic and manual dates¶

Of all these dates, only the modification dates are automatically filled in by the scan.

In fact, when a file is created (manually or automatically), the creation date is APP - Date created blank because the date retrieved electronically is the creation date on the hard disk and not the date corresponding to the initial creation date of the resource.

For example, if the GeoFLA datum of 01/12/2013 is copied to a computer for the first time on 01/03/2014, this is the date that would be uploaded. However, the date to be entered is the one corresponding to the initial creation of the data (i.e. 01/12/2013).

Events: life and evolution of data¶

A resource reference date is a piece of information that represents the life of the resource. There are 3 types, distinguished by colored badges in the application:

creation (in green),
publication (orange),
modification or revision (in blue).

These dates are subject to a few rules:

There must be no more than one creation date;
There may be more than one publication date;
There must be no more than one last revision date, but there may be several revision dates (the most recent is obviously taken into account);
For ease of reading, events are grouped by day.

Validity and updating: data up-to-dateness and obsolescence¶

The Validity period and Update frequency sections define an indication of the time period covered by the resource, which is an indicator of the resource's currency.

For example, this defines the period of validity of a Plan Local d'Urbanisme (PLU).

Metadata dates¶

There are two metadata-related dates in Isogeo that are managed fully automatically.

Metadata creation date¶

It is generated automatically:

when scanning ;
manual creation of the metadata record.

Where to find it :

in APP, it is located in the file's Metadata tab (see dedicated page);
in OpenCatalog, it is not represented;
this is the date that is referenced in the dateStamp field during CSW harvesting (for the national GeoCatalog, for example).

Last metadata modification date¶

It is automatically updated each time the file is edited, either by scanning or manually.

Where to find it :

APP	OpenCatalog