We want to support this field type in ES|QL, ( for filtering / sorting etc) . Not intending to support aggregations on date_nanos (current aggregations truncate the date_nanos to millisecond resolution before aggregating.

Tasks before we can remove the feature flag

• [ESQL] Load and Return Date Nanos Values #109987
• [ESQL] Support basic casting for date nanos #109990
• [ESQL] Support date nanos on functions that take any type #109998
• [ESQL] Support date nanos in binary comparisions #109992
• [ESQL] create TO_DATE_NANOS function #111842
• [ESQL] Support Max & Min aggregation on Date Nanos #110002
• [ESQL] Support Count & Count Distinct aggregations on date nanos #110003
• [ESQL] Support Values aggregation on date nanos #110005
• [ESQL] Sort results by a date nanos field #109988
• [ESQL] Testing for date nanos union type #112885

Additional work required for autocasting

• [ESQL] Date Trunc function should support date nanos #110008
• [ESQL] Support addition and subtraction of date nanos #109995
• Allow for mixed comparisons between millis and nanos #116281
• [ESQL] Support date nanos on Bucket function #118031
• Autocast Keyword to Date in Date Nanos comparisons #118476
• Support Date Nanos for In function #118578
• [ESQL] Support passing Date_Nanos to Date_Format function #109994
• [ESQL] Add a version of DATE_PARSE that returns date nanos #109997
• [ESQL] Support Date Diff function on date nanos #109999
• [ESQL] Support Date Extract function on date nanos #110000
• [ESQL] Extend range of supported timespan literals #111741
• [ESQL] Support autocasting to resolve types between nanosecond dates and millisecond dates #110009
• [ESQL] Union type that accepts date millis and date nanos
• add ::millis and ::nanos as aliases for casting
• Tests for sorting on mixed millisecond/nanosecond