Date "timestamp" value is being returned as milliseconds, not seconds as docs claim.

[michael-newsrx]

Date "timestamp" value is being returned as milliseconds, not seconds as docs claim:

https://github.com/CrossRef/rest-api-doc/blob/master/api_format.md#date

[pdavis8]

We recommend the timestamp runs to seconds and this is how our system will enter the value in the metadata if it is registered through one of our systems. Our members can use up to 19 digits in the timestamp and some members will use the date format YYYYMMDDHHMMSS and others will use their own specific timestamps structures. As per the schema here: http://data.crossref.org/reports/help/schema_doc/4.4.2/schema_4_4_2.html#timestamp

[michael-newsrx]

The "timestamp" property of the Date objects within it appears seems to be derived from the ISO date field. It does not lookup like it is a separate data field being populated by Crossref members. Which makes sense.

[michael-newsrx]

The date objects with "timestamp" and "ISO" values appear to be system generated, not Crossref member supplied. Not asking for an API change, just documentation correction. We use the timestamp value to convert the JSON date into a Java date and only use the timestamp portion, the documentation indicated that I needed to treat the values as seconds, not milliseconds, so initially we were getting some rather fantastical future dates in our data flow.

Example outputs from API (truncated for brevity) with comments added:

{
  "status" : "ok",
  "message-type" : "journal",
  "message" : {
    "last-status-check-time" : 1547590572984 /*milliseconds*/
  }
  }

{
  "status" : "ok",
  "message-type" : "work",
  "message" : {
    "publisher" : "Informa UK Limited",
    "created" : {
      "date-parts" : [ [ 2018, 5, 29 ] ],
      "timestamp" : 1527570400000, //milliseconds
      "date-time" : "2018-05-29T05:06:40Z" //ISO date
    }
}