Hello,
I have an issue with date_histogram on Elastic 7.9.2. The "key_as_string" does not seems to be correct.
I have this index:
PUT https://localhost:9200/test -d '
{
"mappings":{
"properties":{
"date":{
"type":"date",
"format":"yyyy-MM-dd"
}
}
}
}'
Those data:
POST https://localhost:9200/test/_doc/1 -d '{"date": "2022-02-28"}'
POST https://localhost:9200/test/_doc/2 -d '{"date": "2022-06-28"}'
POST https://localhost:9200/test/_doc/3 -d '{"date": "2022-10-28"}'
POST https://localhost:9200/test/_doc/4 -d '{"date": "2021-02-28"}'
POST https://localhost:9200/test/_doc/5 -d '{"date": "2021-06-28"}'
POST https://localhost:9200/test/_doc/6 -d '{"date": "2021-10-28"}'
POST https://localhost:9200/test/_doc/7 -d '{"date": "2020-02-28"}'
POST https://localhost:9200/test/_doc/8 -d '{"date": "2020-06-28"}'
POST https://localhost:9200/test/_doc/9 -d '{"date": "2020-10-28"}'
This query:
{
"from": 0,
"size": 0,
"query": {
"match_all": {}
},
"aggs": {
"date": {
"date_histogram": {
"field": "date",
"format": "YYYY-MM-dd",
"calendar_interval": "1y"
}
}
}
}
Elasticsearch is returning the hereafter result.
"aggregations": {
"date": {
"buckets": [
{
"key_as_string": "2020-01-01",
"key": 1577836800000,
"doc_count": 3}
, {
"key_as_string": "2020-01-01",
"key": 1609459200000,
"doc_count": 3}
, {
"key_as_string": "2021-01-01",
"key": 1640995200000,
"doc_count": 3}]}}
"key_as_string" is wrong whereas the key is correct. Without setting the "format" in the aggregation, the "key_as_string" is correct.
What could be the issue?