complex date objects from the ISMI database

[robcast]

The old ISMI project database OpenMind (OM4) stores historical dates as JSON objects with the following structure:

• state
  • "unknown": no date
  • "not checked": unparsed date in date_in_text
  • "known": date or date range entered in specified calendar
    • calendar_type: calendar the date was entered in
      • "Julian", "Islamic", "Gregorian"
    • input_form: date type
      • "Year"
        • from: first day, until: last day of year (dates in Gregorian calendar, ambiguity of +-2 days when entered in Islamic calendar)
      • "Range"
        • from: first day, until: last day of range (dates in Gregorian calendar, ambiguity of +-2 days when entered in Islamic calendar)
      • "Date"
        • date: given day (date in Gregorian calendar, ambiguity of +-2 days when entered in Islamic calendar)
    • additional_info: textual note with additional information

We have to extract as much as possible of this data in the migration to the new RDF database with a CIDOC-CRM-based data model.

A sample file with dates of each type:
ismi-om4-date-samples.json.txt

Does it make sense to add this data file to the repository?

[rlskoeser]

@robcast let's use this issue to track updating the ISMI example data and started on an example notebook to work with it.

[robcast]

I updated the samples and README with the new CIDOC-CRM RDF model for the development branch: #104