Implement date range hard options (century, month, decade)

[jduss4]

Right now date_field.year is supported, but we should implement some more non-adjustable ranges, also

• month ?
• decade
• quarter century
• century

If these are implemented, the behavior should be implementable if the backend was switched to solr.

[jduss4]

Will probably have to use date range query to get at decade and century, unfortunately.

However, you can do something like this, if you don't care that much about accuracy!

      "date.3650d": {
        "1890-01-20": 450,
        "1910-01-16": 349,
        "1920-01-14": 330,
        "1880-01-23": 204,
        "1900-01-18": 187,
        "1930-01-11": 139,
        "1950-01-06": 138,

[jduss4]

Date histogram docs (what API uses now): https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-datehistogram-aggregation.html

Date range docs (what API may need to use for decade / century): https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-bucket-daterange-aggregation.html

[karindalziel]

For now let's handle this using custom fields on ingest