[[search-aggregations-bucket-daterange-aggregation]]
=== Date Range Aggregation

A range aggregation that is dedicated for date values. The main difference
between this aggregation and the normal
<<search-aggregations-bucket-range-aggregation,range>>
aggregation is that the `from` and `to` values can be expressed in
<<date-math,Date Math>> expressions, and it is also possible to specify a date
format by which the `from` and `to` response fields will be returned.
Note that this aggregation includes the `from` value and excludes the `to` value
for each range.

Example:

[source,console]
--------------------------------------------------
POST /sales/_search?size=0
{
    "aggs": {
        "range": {
            "date_range": {
                "field": "date",
                "format": "MM-yyyy",
                "ranges": [
                    { "to": "now-10M/M" }, <1>
                    { "from": "now-10M/M" } <2>
                ]
            }
        }
    }
}
--------------------------------------------------
// TEST[setup:sales s/now-10M\/M/10-2015/]

<1> < now minus 10 months, rounded down to the start of the month.
<2> >= now minus 10 months, rounded down to the start of the month.

In the example above, we created two range buckets, the first will "bucket" all
documents dated prior to 10 months ago and the second will "bucket" all
documents dated since 10 months ago

Response:

[source,console-result]
--------------------------------------------------
{
    ...
    "aggregations": {
        "range": {
            "buckets": [
                {
                    "to": 1.4436576E12,
                    "to_as_string": "10-2015",
                    "doc_count": 7,
                    "key": "*-10-2015"
                },
                {
                    "from": 1.4436576E12,
                    "from_as_string": "10-2015",
                    "doc_count": 0,
                    "key": "10-2015-*"
                }
            ]
        }
    }
}
--------------------------------------------------
// TESTRESPONSE[s/\.\.\./"took": $body.took,"timed_out": false,"_shards": $body._shards,"hits": $body.hits,/]

==== Missing Values

The `missing` parameter defines how documents that are missing a value should
be treated. By default they will be ignored but it is also possible to treat
them as if they had a value. This is done by adding a set of fieldname :
value mappings to specify default values per field.

[source,console]
--------------------------------------------------
POST /sales/_search?size=0
{
   "aggs": {
       "range": {
           "date_range": {
               "field": "date",
               "missing": "1976/11/30",
               "ranges": [
                  { 
                    "key": "Older",
                    "to": "2016/02/01" 
                  }, <1>
                  { 
                    "key": "Newer",
                    "from": "2016/02/01", 
                    "to" : "now/d" 
                  }
              ]
          }
      }
   }
}
--------------------------------------------------
// TEST[setup:sales]

<1> Documents without a value in the `date` field will be added to the "Older"
bucket, as if they had a date value of "1976-11-30". 

[[date-format-pattern]]
==== Date Format/Pattern

NOTE: this information was copied from
https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html[DateTimeFormatter]

All ASCII letters are reserved as format pattern letters, which are defined
as follows:

[options="header"]
|=======
|Symbol |Meaning                    |Presentation |Examples
|G      |era                        |text         |AD; Anno Domini; A
|u      |year                       |year         |2004; 04
|y      |year-of-era                |year         |2004; 04
|D      |day-of-year                |number       |189
|M/L    |month-of-year              |number/text  |7; 07; Jul; July; J
|d      |day-of-month               |number       |10

|Q/q    |quarter-of-year            |number/text  |3; 03; Q3; 3rd quarter
|Y      |week-based-year            |year         |1996; 96
|w      |week-of-week-based-year    |number       |27
|W      |week-of-month              |number       |4
|E      |day-of-week                |text         |Tue; Tuesday; T
|e/c    |localized day-of-week      |number/text  |2; 02; Tue; Tuesday; T
|F      |week-of-month              |number       |3

|a      |am-pm-of-day               |text         |PM
|h      |clock-hour-of-am-pm (1-12) |number       |12
|K      |hour-of-am-pm (0-11)       |number       |0
|k      |clock-hour-of-am-pm (1-24) |number       |0

|H      |hour-of-day (0-23)         |number       |0
|m      |minute-of-hour             |number       |30
|s      |second-of-minute           |number       |55
|S      |fraction-of-second         |fraction     |978
|A      |milli-of-day               |number       |1234
|n      |nano-of-second             |number       |987654321
|N      |nano-of-day                |number       |1234000000

|V      |time-zone ID               |zone-id      |America/Los_Angeles; Z; -08:30
|z      |time-zone name             |zone-name    |Pacific Standard Time; PST
|O      |localized zone-offset      |offset-O     |GMT+8; GMT+08:00; UTC-08:00;
|X      |zone-offset 'Z' for zero   |offset-X     |Z; -08; -0830; -08:30; -083015; -08:30:15;
|x      |zone-offset                |offset-x     |+0000; -08; -0830; -08:30; -083015; -08:30:15;
|Z      |zone-offset                |offset-Z     |+0000; -0800; -08:00;

|p      |pad next                   |pad modifier |1
|'      |escape for text            |delimiter
|''     |single quote               |literal      |'
|[      |optional section start
|]      |optional section end
|#      |reserved for future use
|{      |reserved for future use
|}      |reserved for future use
|=======

The count of pattern letters determines the format.

Text:: The text style is determined based on the number of pattern letters
used. Less than 4 pattern letters will use the short form. Exactly 4
pattern letters will use the full form. Exactly 5 pattern letters will use
the narrow form. Pattern letters `L`, `c`, and `q` specify the stand-alone
form of the text styles.

Number:: If the count of letters is one, then the value is output using
the minimum number of digits and without padding. Otherwise, the count of
digits is used as the width of the output field, with the value
zero-padded as necessary. The following pattern letters have constraints
on the count of letters. Only one letter of `c` and `F` can be specified.
Up to two letters of `d`, `H`, `h`, `K`, `k`, `m`, and `s` can be
specified. Up to three letters of `D` can be specified.

Number/Text:: If the count of pattern letters is 3 or greater, use the
Text rules above. Otherwise use the Number rules above.

Fraction:: Outputs the nano-of-second field as a fraction-of-second. The
nano-of-second value has nine digits, thus the count of pattern letters is
from 1 to 9. If it is less than 9, then the nano-of-second value is
truncated, with only the most significant digits being output.

Year:: The count of letters determines the minimum field width below which
padding is used. If the count of letters is two, then a reduced two digit
form is used. For printing, this outputs the rightmost two digits. For
parsing, this will parse using the base value of 2000, resulting in a year
within the range 2000 to 2099 inclusive. If the count of letters is less
than four (but not two), then the sign is only output for negative years
as per `SignStyle.NORMAL`. Otherwise, the sign is output if the pad width is
exceeded, as per `SignStyle.EXCEEDS_PAD`.

ZoneId:: This outputs the time-zone ID, such as `Europe/Paris`. If the
count of letters is two, then the time-zone ID is output. Any other count
of letters throws `IllegalArgumentException`.

Zone names:: This outputs the display name of the time-zone ID. If the
count of letters is one, two or three, then the short name is output. If
the count of letters is four, then the full name is output. Five or more
letters throws `IllegalArgumentException`.

Offset X and x:: This formats the offset based on the number of pattern
letters. One letter outputs just the hour, such as `+01`, unless the
minute is non-zero in which case the minute is also output, such as
`+0130`. Two letters outputs the hour and minute, without a colon, such as
`+0130`. Three letters outputs the hour and minute, with a colon, such as
`+01:30`. Four letters outputs the hour and minute and optional second,
without a colon, such as `+013015`. Five letters outputs the hour and
minute and optional second, with a colon, such as `+01:30:15`. Six or
more letters throws `IllegalArgumentException`. Pattern letter `X` (upper
case) will output `Z` when the offset to be output would be zero,
whereas pattern letter `x` (lower case) will output `+00`, `+0000`, or
`+00:00`.

Offset O:: This formats the localized offset based on the number of
pattern letters. One letter outputs the short form of the localized
offset, which is localized offset text, such as `GMT`, with hour without
leading zero, optional 2-digit minute and second if non-zero, and colon,
for example `GMT+8`. Four letters outputs the full form, which is
localized offset text, such as `GMT, with 2-digit hour and minute
field, optional second field if non-zero, and colon, for example
`GMT+08:00`. Any other count of letters throws
`IllegalArgumentException`.

Offset Z:: This formats the offset based on the number of pattern letters.
One, two or three letters outputs the hour and minute, without a colon,
such as `+0130`. The output will be `+0000` when the offset is zero.
Four letters outputs the full form of localized offset, equivalent to
four letters of Offset-O. The output will be the corresponding localized
offset text if the offset is zero. Five letters outputs the hour,
minute, with optional second if non-zero, with colon. It outputs `Z` if
the offset is zero. Six or more letters throws IllegalArgumentException.

Optional section:: The optional section markers work exactly like calling
`DateTimeFormatterBuilder.optionalStart()` and
`DateTimeFormatterBuilder.optionalEnd()`.

Pad modifier:: Modifies the pattern that immediately follows to be padded
with spaces. The pad width is determined by the number of pattern letters.
This is the same as calling `DateTimeFormatterBuilder.padNext(int)`.

For example, `ppH` outputs the hour-of-day padded on the left with spaces to a width of 2.

Any unrecognized letter is an error. Any non-letter character, other than
`[`, `]`, `{`, `}`, `#` and the single quote will be output directly.
Despite this, it is recommended to use single quotes around all characters
that you want to output directly to ensure that future changes do not
break your application.


[[time-zones]]
==== Time zone in date range aggregations

Dates can be converted from another time zone to UTC by specifying the
`time_zone` parameter.

Time zones may either be specified as an ISO 8601 UTC offset (e.g. +01:00 or
-08:00) or as one of the time zone ids from the TZ database.

The `time_zone` parameter is also applied to rounding in date math expressions.
As an example, to round to the beginning of the day in the CET time zone, you
can do the following:

[source,console]
--------------------------------------------------
POST /sales/_search?size=0
{
   "aggs": {
       "range": {
           "date_range": {
               "field": "date",
               "time_zone": "CET",
               "ranges": [
                  { "to": "2016/02/01" }, <1>
                  { "from": "2016/02/01", "to" : "now/d" }, <2>
                  { "from": "now/d" }
              ]
          }
      }
   }
}
--------------------------------------------------
// TEST[setup:sales]

<1> This date will be converted to `2016-02-01T00:00:00.000+01:00`.
<2> `now/d` will be rounded to the beginning of the day in the CET time zone.

==== Keyed Response

Setting the `keyed` flag to `true` will associate a unique string key with each
bucket and return the ranges as a hash rather than an array:

[source,console]
--------------------------------------------------
POST /sales/_search?size=0
{
    "aggs": {
        "range": {
            "date_range": {
                "field": "date",
                "format": "MM-yyy",
                "ranges": [
                    { "to": "now-10M/M" },
                    { "from": "now-10M/M" }
                ],
                "keyed": true
            }
        }
    }
}
--------------------------------------------------
// TEST[setup:sales s/now-10M\/M/10-2015/]

Response:

[source,console-result]
--------------------------------------------------
{
    ...
    "aggregations": {
        "range": {
            "buckets": {
                "*-10-2015": {
                    "to": 1.4436576E12,
                    "to_as_string": "10-2015",
                    "doc_count": 7
                },
                "10-2015-*": {
                    "from": 1.4436576E12,
                    "from_as_string": "10-2015",
                    "doc_count": 0
                }
            }
        }
    }
}
--------------------------------------------------
// TESTRESPONSE[s/\.\.\./"took": $body.took,"timed_out": false,"_shards": $body._shards,"hits": $body.hits,/]

It is also possible to customize the key for each range:

[source,console]
--------------------------------------------------
POST /sales/_search?size=0
{
    "aggs": {
        "range": {
            "date_range": {
                "field": "date",
                "format": "MM-yyy",
                "ranges": [
                    { "from": "01-2015",  "to": "03-2015", "key": "quarter_01" },
                    { "from": "03-2015", "to": "06-2015", "key": "quarter_02" }
                ],
                "keyed": true
            }
        }
    }
}
--------------------------------------------------
// TEST[setup:sales]

Response:

[source,console-result]
--------------------------------------------------
{
    ...
    "aggregations": {
        "range": {
            "buckets": {
                "quarter_01": {
                    "from": 1.4200704E12,
                    "from_as_string": "01-2015",
                    "to": 1.425168E12,
                    "to_as_string": "03-2015",
                    "doc_count": 5
                },
                "quarter_02": {
                    "from": 1.425168E12,
                    "from_as_string": "03-2015",
                    "to": 1.4331168E12,
                    "to_as_string": "06-2015",
                    "doc_count": 2
                }
            }
        }
    }
}
--------------------------------------------------
// TESTRESPONSE[s/\.\.\./"took": $body.took,"timed_out": false,"_shards": $body._shards,"hits": $body.hits,/]
