modified date metadata field reflects harvest date (not date last modified by publisher/portal)

[emillipede]

for example, in this dataset https://www.lacounts.org/dataset/tsunami-inundation-zones the last modified date is Tuesday 26 March. on the portal site, there's no record of an update http://geohub.lacity.org/datasets/ffaf33ba67264818a729dc97a384c064_6

[emillipede]

please clarify what "modified date" reflects and if there was a modification to this dataset on/around 26 March

thank you!

[amercader]

@emillipede The "Modified" date in the Metadata section reflects the modification date advertised by the publisher in the metadata we harvest automatically.

In the Tsunami Inundation Zones dataset this is how it looks like on the JSON-LD dump that we harvest:

    {
      "@type": "dcat:Dataset",
      "identifier": "http://geohub.lacity.org/datasets/ffaf33ba67264818a729dc97a384c064_6",
      "title": "Tsunami Inundation Zones",
      "description": "Area modelled to be inundated by a tsunami",
      "keyword": [
        "Los Angeles",
        "LA",
        "County of LA",
        "hazards",
        "safety",
        "earthquake hazards",
        "tsunami hazards",
        "boundaries",
        "a safe city"
      ],
      "issued": "2015-11-17T01:48:09.000Z",
      "modified": "2019-03-26T16:14:59.928Z",
      "publisher": {
        "name": "City of Los Angeles Hub"
      },
      "contactPoint": {
        "@type": "vcard:Contact",
        "fn": "Kirk Bishop",
        "hasEmail": "mailto:mayor.opendata@lacity.org"
      },
      "accessLevel": "public",

      [...]

      "landingPage": "http://geohub.lacity.org/datasets/ffaf33ba67264818a729dc97a384c064_6",
      "webService": "http://public.gis.lacounty.gov/public/rest/services/LACounty_Dynamic/Hazards/MapServer/6",
      "license": "https://hub.arcgis.com/api/v2/datasets/ffaf33ba67264818a729dc97a384c064_6/license",
      "spatial": "-118.944802415,33.7001774114,-118.088643462,34.0499505044",
      "theme": [
        "geospatial"
      ]
    }

Note the modified key. I know that this is not consistent with the date shown on the geohub page, and that it probably reflects some edit done on the GeoHub metadata, but we have no way of knowing this when storing it on our side.

So to sum up, Modified stores the last update date that the publisher provides us on the metadata.

[emillipede]

Thank you for investigating @amercader , good to know. I'll follow up with @carlacasilli to see if she'd like to address this possibility in the site FAQ

[carlacasilli]

Thanks for this info, @amercader and @emillipede. Yes, Emily, please add an explanation to the Datasets portion of the FAQs. Thanks!