--- mapped_pages: - https://www.elastic.co/guide/en/elasticsearch/reference/current/mapping-date-format.html --- # format [mapping-date-format] In JSON documents, dates are represented as strings. Elasticsearch uses a set of preconfigured formats to recognize and parse these strings into a long value representing *milliseconds-since-the-epoch* in UTC. Besides the [built-in formats](#built-in-date-formats), your own [custom formats](#custom-date-formats) can be specified using the familiar `yyyy/MM/dd` syntax: ```console PUT my-index-000001 { "mappings": { "properties": { "date": { "type": "date", "format": "yyyy-MM-dd" } } } } ``` Many APIs which support date values also support [date math](/reference/elasticsearch/rest-apis/common-options.md#date-math) expressions, such as `now-1m/d` — the current time, minus one month, rounded down to the nearest day. ## Custom date formats [custom-date-formats] Completely customizable date formats are supported. The syntax for these is explained in [DateTimeFormatter docs](https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/time/format/DateTimeFormatter.html). Note that while the built-in formats for week dates use the ISO definition of weekyears, custom formatters using the `Y`, `W`, or `w` field specifiers use the JDK locale definition of weekyears. This can result in different values between the built-in formats and custom formats for week dates. ## Built-in formats [built-in-date-formats] Most of the below formats have a `strict` companion format, which means that year, month and day parts of the month must use respectively 4, 2 and 2 digits exactly, potentially prepending zeros. For instance a date like `5/11/1` would be considered invalid and would need to be rewritten to `2005/11/01` to be accepted by the date parser. To use them, you need to prepend `strict_` to the name of the date format, for instance `strict_date_optional_time` instead of `date_optional_time`. These strict date formats are especially useful when [date fields are dynamically mapped](docs-content://manage-data/data-store/mapping/dynamic-field-mapping.md#date-detection) in order to make sure to not accidentally map irrelevant strings as dates. The following tables lists all the defaults ISO formats supported: `epoch_millis` : A formatter for the number of milliseconds since the epoch. Note, that this timestamp is subject to the limits of a Java `Long.MIN_VALUE` and `Long.MAX_VALUE`. `epoch_second` : A formatter for the number of seconds since the epoch. Note, that this timestamp is subject to the limits of a Java `Long.MIN_VALUE` and `Long. MAX_VALUE` divided by 1000 (the number of milliseconds in a second). $$$strict-date-time$$$`date_optional_time` or `strict_date_optional_time` : A generic ISO datetime parser, where the date must include the year at a minimum, and the time (separated by `T`), is optional. Examples: `yyyy-MM-dd'T'HH:mm:ss.SSSZ` or `yyyy-MM-dd`. ``` NOTE: When using `date_optional_time`, the parsing is lenient and will attempt to parse numbers as a year (e.g. `292278994` will be parsed as a year). This can lead to unexpected results when paired with a numeric focused format like `epoch_second` and `epoch_millis`. It is recommended you use `strict_date_optional_time` when pairing with a numeric focused format. ``` $$$strict-date-time-nanos$$$`strict_date_optional_time_nanos` : A generic ISO datetime parser, where the date must include the year at a minimum, and the time (separated by `T`), is optional. The fraction of a second part has a nanosecond resolution. Examples: `yyyy-MM-dd'T'HH:mm:ss.SSSSSSZ` or `yyyy-MM-dd`. `basic_date` : A basic formatter for a full date as four digit year, two digit month of year, and two digit day of month: `yyyyMMdd`. `basic_date_time` : A basic formatter that combines a basic date and time, separated by a *T*: `yyyyMMdd'T'HHmmss.SSSZ`. `basic_date_time_no_millis` : A basic formatter that combines a basic date and time without millis, separated by a *T*: `yyyyMMdd'T'HHmmssZ`. `basic_ordinal_date` : A formatter for a full ordinal date, using a four digit year and three digit dayOfYear: `yyyyDDD`. `basic_ordinal_date_time` : A formatter for a full ordinal date and time, using a four digit year and three digit dayOfYear: `yyyyDDD'T'HHmmss.SSSZ`. `basic_ordinal_date_time_no_millis` : A formatter for a full ordinal date and time without millis, using a four digit year and three digit dayOfYear: `yyyyDDD'T'HHmmssZ`. `basic_time` : A basic formatter for a two digit hour of day, two digit minute of hour, two digit second of minute, three digit millis, and time zone offset: `HHmmss.SSSZ`. `basic_time_no_millis` : A basic formatter for a two digit hour of day, two digit minute of hour, two digit second of minute, and time zone offset: `HHmmssZ`. `basic_t_time` : A basic formatter for a two digit hour of day, two digit minute of hour, two digit second of minute, three digit millis, and time zone off set prefixed by *T*: `'T'HHmmss.SSSZ`. `basic_t_time_no_millis` : A basic formatter for a two digit hour of day, two digit minute of hour, two digit second of minute, and time zone offset prefixed by *T*: `'T'HHmmssZ`. `basic_week_date` or `strict_basic_week_date` : A basic formatter for a full date as four digit weekyear, two digit week of weekyear, and one digit day of week: `xxxx'W'wwe`. `basic_week_date_time` or `strict_basic_week_date_time` : A basic formatter that combines a basic weekyear date and time, separated by a *T*: `xxxx'W'wwe'T'HHmmss.SSSZ`. `basic_week_date_time_no_millis` or `strict_basic_week_date_time_no_millis` : A basic formatter that combines a basic weekyear date and time without millis, separated by a *T*: `xxxx'W'wwe'T'HHmmssZ`. `date` or `strict_date` : A formatter for a full date as four digit year, two digit month of year, and two digit day of month: `yyyy-MM-dd`. `date_hour` or `strict_date_hour` : A formatter that combines a full date and two digit hour of day: `yyyy-MM-dd'T'HH`. `date_hour_minute` or `strict_date_hour_minute` : A formatter that combines a full date, two digit hour of day, and two digit minute of hour: `yyyy-MM-dd'T'HH:mm`. `date_hour_minute_second` or `strict_date_hour_minute_second` : A formatter that combines a full date, two digit hour of day, two digit minute of hour, and two digit second of minute: `yyyy-MM-dd'T'HH:mm:ss`. `date_hour_minute_second_fraction` or `strict_date_hour_minute_second_fraction` : A formatter that combines a full date, two digit hour of day, two digit minute of hour, two digit second of minute, and three digit fraction of second: `yyyy-MM-dd'T'HH:mm:ss.SSS`. `date_hour_minute_second_millis` or `strict_date_hour_minute_second_millis` : A formatter that combines a full date, two digit hour of day, two digit minute of hour, two digit second of minute, and three digit fraction of second: `yyyy-MM-dd'T'HH:mm:ss.SSS`. `date_time` or `strict_date_time` : A formatter that combines a full date and time, separated by a *T*: `yyyy-MM-dd'T'HH:mm:ss.SSSZ`. `date_time_no_millis` or `strict_date_time_no_millis` : A formatter that combines a full date and time without millis, separated by a *T*: `yyyy-MM-dd'T'HH:mm:ssZ`. `hour` or `strict_hour` : A formatter for a two digit hour of day: `HH` `hour_minute` or `strict_hour_minute` : A formatter for a two digit hour of day and two digit minute of hour: `HH:mm`. `hour_minute_second` or `strict_hour_minute_second` : A formatter for a two digit hour of day, two digit minute of hour, and two digit second of minute: `HH:mm:ss`. `hour_minute_second_fraction` or `strict_hour_minute_second_fraction` : A formatter for a two digit hour of day, two digit minute of hour, two digit second of minute, and three digit fraction of second: `HH:mm:ss.SSS`. `hour_minute_second_millis` or `strict_hour_minute_second_millis` : A formatter for a two digit hour of day, two digit minute of hour, two digit second of minute, and three digit fraction of second: `HH:mm:ss.SSS`. `ordinal_date` or `strict_ordinal_date` : A formatter for a full ordinal date, using a four digit year and three digit dayOfYear: `yyyy-DDD`. `ordinal_date_time` or `strict_ordinal_date_time` : A formatter for a full ordinal date and time, using a four digit year and three digit dayOfYear: `yyyy-DDD'T'HH:mm:ss.SSSZ`. `ordinal_date_time_no_millis` or `strict_ordinal_date_time_no_millis` : A formatter for a full ordinal date and time without millis, using a four digit year and three digit dayOfYear: `yyyy-DDD'T'HH:mm:ssZ`. `time` or `strict_time` : A formatter for a two digit hour of day, two digit minute of hour, two digit second of minute, three digit fraction of second, and time zone offset: `HH:mm:ss.SSSZ`. `time_no_millis` or `strict_time_no_millis` : A formatter for a two digit hour of day, two digit minute of hour, two digit second of minute, and time zone offset: `HH:mm:ssZ`. `t_time` or `strict_t_time` : A formatter for a two digit hour of day, two digit minute of hour, two digit second of minute, three digit fraction of second, and time zone offset prefixed by *T*: `'T'HH:mm:ss.SSSZ`. `t_time_no_millis` or `strict_t_time_no_millis` : A formatter for a two digit hour of day, two digit minute of hour, two digit second of minute, and time zone offset prefixed by *T*: `'T'HH:mm:ssZ`. `week_date` or `strict_week_date` : A formatter for a full date as four digit weekyear, two digit week of weekyear, and one digit day of week: `YYYY-'W'ww-e`. This uses the ISO week-date definition. `week_date_time` or `strict_week_date_time` : A formatter that combines a full weekyear date and time, separated by a *T*: `YYYY-'W'ww-e'T'HH:mm:ss.SSSZ`. This uses the ISO week-date definition. `week_date_time_no_millis` or `strict_week_date_time_no_millis` : A formatter that combines a full weekyear date and time without millis, separated by a *T*: `YYYY-'W'ww-e'T'HH:mm:ssZ`. This uses the ISO week-date definition. `weekyear` or `strict_weekyear` : A formatter for a four digit weekyear: `YYYY`. This uses the ISO week-date definition. `weekyear_week` or `strict_weekyear_week` : A formatter for a four digit weekyear and two digit week of weekyear: `YYYY-'W'ww`. This uses the ISO week-date definition. `weekyear_week_day` or `strict_weekyear_week_day` : A formatter for a four digit weekyear, two digit week of weekyear, and one digit day of week: `YYYY-'W'ww-e`. This uses the ISO week-date definition. `year` or `strict_year` : A formatter for a four digit year: `yyyy`. `year_month` or `strict_year_month` : A formatter for a four digit year and two digit month of year: `yyyy-MM`. `year_month_day` or `strict_year_month_day` : A formatter for a four digit year, two digit month of year, and two digit day of month: `yyyy-MM-dd`.