To query and sort events by their next upcoming date from an array of dates in Elasticsearch, you need to combine a range filter with a custom script-based sort. Here's how to achieve this:

Filtering Future Events

Use a range query to include events with at least one date in the future:

json

"query": { "bool": { "filter": { "range": { "OccursOn": { "gte": "now" } } } } }

This ensures only events with dates occurring now or later are included134.

Sorting by Next Occurrence

Use a Painless script in the sort to find the earliest future date in the OccursOn array:

json

"sort": [ { "_script": { "type": "number", "script": { "lang": "painless", "source": """ long now = new Date().getTime(); long nextDate = Long.MAX_VALUE; for (def date : doc['OccursOn']) { long timestamp = date.toInstant().toEpochMilli(); if (timestamp >= now && timestamp < nextDate) { nextDate = timestamp; } } return nextDate; """ }, "order": "asc" } } ]

This script24:

1. Gets the current timestamp

2. Iterates through all event dates

3. Identifies the earliest date that hasn't occurred yet

4. Sorts events ascending by this calculated next date

Complete Example

json

{ "query": { "bool": { "filter": { "range": { "OccursOn": { "gte": "now" } } } } }, "sort": [ { "_script": { "type": "number", "script": { "lang": "painless", "source": """ long now = new Date().getTime(); long nextDate = Long.MAX_VALUE; for (def date : doc['OccursOn']) { long timestamp = date.toInstant().toEpochMilli(); if (timestamp >= now && timestamp < nextDate) { nextDate = timestamp; } } return nextDate; """ }, "order": "asc" } } ] }

Key Considerations

• Ensure OccursOn is mapped as a date type25

• Script sorting has performance implications for large datasets

• For better performance, consider pre-calculating the next occurrence date during indexing

• Use parameterized now in production for consistent timestamps across distributed systems24

This solution filters events with future dates and sorts them by their earliest upcoming occurrence using Elasticsearch's script sorting capabilities