--- title: "epoch_ns" slug: "dev-database-reference-sql-functions-date-time-epoch-ns" updated: 2026-10-30T18:19:01Z published: 2026-10-30T18:19:01Z canonical: "docs.vastdata.com/dev-database-reference-sql-functions-date-time-epoch-ns" --- > ## Documentation Index > Fetch the complete documentation index at: https://docs.vastdata.com/llms.txt > Use this file to discover all available pages before exploring further. # epoch_ns *Applies to VAST Cluster 5.5.* *[Functions](/develop/docs/dev-database-reference-sql-functions-index) › [Date and time functions](/develop/docs/dev-database-reference-sql-functions-date-time) › Epoch values.* Returns the number of whole nanoseconds since 1970-01-01 00:00:00 of a date or timestamp, as a `BIGINT`. On a time of day it returns the nanoseconds since midnight, and on an interval its length in nanoseconds. It's the only epoch function that keeps the nanoseconds of a `TIMESTAMP_NS`. ## Syntax ``` epoch_ns(value) ``` | Argument | Type | Description | | --- | --- | --- | | `value` | `DATE`, `TIMESTAMP_NS`, `TIMESTAMP` (also `TIMESTAMP_MS`, `TIMESTAMP_S`), `TIMESTAMP WITH TIME ZONE`, `TIME`, `TIME WITH TIME ZONE` or `INTERVAL` | The value to convert to nanoseconds. | **Returns:** `BIGINT`. ## Set up the examples The examples connect with the ADBC driver, as in [VAST Query Engine (ADBC)](/develop/docs/dev-database-integrations-adbc), and work in a schema called `docs_sql_fn_date_time_epoch_ns`. Set `QE_ENDPOINT`, `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY` and `VASTDB_BUCKET` ([SQL reference](/develop/docs/dev-database-reference-sql-index#example-connect-and-use-a-transaction)), and run the blocks in order in one Python session. Below each block is the output you should see. This block connects, defines the `run()` and `plan()` helpers, and creates a table of five events. Each has a date (`d`), a timestamp (`ts`), a time of day (`t`) and a timestamp with nanoseconds (`tns`). Row 4 has no values, and row 5 is the last moment of 1969: ``` import os import re import adbc_driver_manager import adbc_driver_manager.dbapi as dbapi import adbc_driver_vastdb BUCKET = os.environ["VASTDB_BUCKET"] SCHEMA = f'"{BUCKET}/docs_sql_fn_date_time_epoch_ns"' conn = dbapi.connect( driver=adbc_driver_vastdb.get_driver_path(), db_kwargs={ "vast.db.endpoint": os.environ["QE_ENDPOINT"], "vast.db.access_key": os.environ["AWS_ACCESS_KEY_ID"], "vast.db.secret_key": os.environ["AWS_SECRET_ACCESS_KEY"], }, autocommit=True, ) def server_message(e): """The server's message in a driver error, without the request ID or the echoed statement.""" text = re.sub(r"\[req=0x[0-9a-f]+\]: ", "", str(e)) found = (re.search(r'message: "(.*?)", request_id', text, re.S) or re.search(r"description: (.*)\)", text, re.S)) message = found.group(1) if found else text.strip().splitlines()[-1] message = re.sub(r"^Plan query: '.*?' failed with: ", "", message, flags=re.S) message = re.split(r"\\n|\n", message)[0].replace('\\"', '"') return message.replace(BUCKET, "") def run(sql): """Run one statement. Print the rows it returns, or the error.""" try: with conn.cursor() as cur: cur.execute(sql) rows = cur.fetchall() if cur.description else [] except (adbc_driver_manager.Error, OSError) as e: print(f"{type(e).__name__}: {server_message(e)}") else: print(rows) def plan(sql): """Print the plan without its ~N Rows lines: the table's row count, which can still be 0 just after an insert.""" with conn.cursor() as cur: cur.execute("EXPLAIN " + sql) steps = cur.fetchall()[0][1] print("\n".join(line for line in steps.splitlines() if "Rows" not in line)) TABLE = f"{SCHEMA}.events" run(f"CREATE SCHEMA IF NOT EXISTS {SCHEMA}") run(f"CREATE TABLE IF NOT EXISTS {TABLE} (id BIGINT, d DATE, ts TIMESTAMP, t TIME, tns TIMESTAMP_NS)") run(f"INSERT INTO {TABLE} VALUES " "(1, DATE '2026-02-28', TIMESTAMP '2026-02-28 23:15:00', TIME '23:15:00', " "CAST('2026-02-28 23:15:00.123456789' AS TIMESTAMP_NS)), " "(2, DATE '2026-03-01', TIMESTAMP '2026-03-01 08:30:45.123456', TIME '08:30:45.123456', " "CAST('2026-03-01 08:30:45.123456' AS TIMESTAMP_NS)), " "(3, DATE '2024-12-30', TIMESTAMP '2024-12-30 12:00:00', TIME '12:00:00', " "CAST('2024-12-30 12:00:00' AS TIMESTAMP_NS)), " "(4, NULL, NULL, NULL, NULL), " "(5, DATE '1969-12-31', TIMESTAMP '1969-12-31 23:59:59.999999', TIME '23:59:59.999999', " "CAST('1969-12-31 23:59:59.999999999' AS TIMESTAMP_NS))") ``` ``` [] [] [(5,)] ``` ## What it does `epoch_ns` converts a value to whole nanoseconds, as a `BIGINT`: | Argument type | What it returns | Example | Result | | --- | --- | --- | --- | | `TIMESTAMP_NS` | Nanoseconds since 1970-01-01 00:00:00, exactly | `epoch_ns(TIMESTAMP_NS '2024-02-29 13:45:30.123456789')` | `1709214330123456789` | | `TIMESTAMP` | Nanoseconds since 1970-01-01 00:00:00; the last three digits are `000` | `epoch_ns(TIMESTAMP '2024-02-29 13:45:30.123456')` | `1709214330123456000` | | `DATE` | Nanoseconds since 1970-01-01 at the date's midnight | `epoch_ns(DATE '2024-02-29')` | `1709164800000000000` | | `TIME` | Nanoseconds since midnight | `epoch_ns(TIME '13:45:30.123456')` | `49530123456000` | | `INTERVAL` | The interval's length in nanoseconds | `epoch_ns(INTERVAL '1 year')` | `31104000000000000` | Values before 1970 are negative: row 5's `tns`, one nanosecond before 1970, gives `-1`, and its `ts`, one microsecond before 1970, gives `-1000`. A `BIGINT` of nanoseconds covers a limited span around 1970: `epoch_ns` works on `2262-04-11 23:47:16` and on `1677-09-21 00:12:44`, but fails on `2262-04-12 00:00:00` and on `1677-09-21 00:00:00` (see [Limitations and errors](/develop/docs/dev-database-reference-sql-functions-date-time-epoch-ns#limitations-and-errors)). On a `TIMESTAMP WITH TIME ZONE`, the nanoseconds count from 1970-01-01 00:00:00 UTC, so the offset is applied: `epoch_ns(TIMESTAMPTZ '2024-02-29 13:45:30.123456+02')` is `1709207130123456000`. On a `TIME WITH TIME ZONE`, the offset isn't applied. On an `INTERVAL`, a month is 30 days and a year is 12 months (360 days). ## NULLs and edge cases | Input | Result | | --- | --- | | A NULL value (row 4) | `NULL` | | `DATE 'infinity'`, `TIMESTAMP '-infinity'` | `NULL` | | `TIMESTAMP '2262-04-11 23:47:16'` | `9223372036000000000` | | `TIMESTAMP '1677-09-21 00:12:44'` | `-9223372036000000000` | | `INTERVAL '-1 year -2 months -3 days -04:05:06.789'` | `-36561906789000000` | | `TIMESTAMP '2262-04-12 00:00:00'` (past the range) | Error: a `Conversion Error` that starts `Could not convert Timestamp(US) to Timestamp(NS` | | `DATE '0001-01-01'` (outside the range) | Error: `Could not convert DATE (0001-01-01) to nanoseconds` | | An untyped `NULL`: `epoch_ns(NULL)` | Error: `Could not choose a best candidate function for the function call "epoch_ns("NULL")"` | | A string | Error: `Could not choose a best candidate function`; cast it to `TIMESTAMP_NS` or `TIMESTAMP` first | | A number, boolean, `BLOB` or list | Error: `No function matches the given name and argument types`, for example `'epoch_ns(INTEGER_LITERAL)'` | The same cases, as the cluster returns them. They use the table and helpers from [Set up the examples](/develop/docs/dev-database-reference-sql-functions-date-time-epoch-ns#set-up-the-examples): ``` run(f"SELECT id, epoch_ns(ts), epoch_ns(tns) FROM {TABLE} WHERE id = 4") run("SELECT epoch_ns(DATE 'infinity'), epoch_ns(TIMESTAMP '-infinity'), epoch_ns(TIMESTAMP '2262-04-11 23:47:16'), " "epoch_ns(TIMESTAMP '1677-09-21 00:12:44'), epoch_ns(INTERVAL '-1 year -2 months -3 days -04:05:06.789')") run("SELECT epoch_ns(TIMESTAMP '2262-04-12 00:00:00')") run("SELECT epoch_ns(DATE '0001-01-01')") run("SELECT epoch_ns(NULL)") run("SELECT epoch_ns('2024-02-29 13:45:30')") run("SELECT epoch_ns(123)") ``` ``` [(4, None, None)] [(None, None, 9223372036000000000, -9223372036000000000, -36561906789000000)] InternalError: Conversion Error: Could not convert Timestamp(US) to Timestamp(NS) InternalError: Conversion Error: Could not convert DATE (0001-01-01) to nanoseconds InternalError: Binder Error: Could not choose a best candidate function for the function call "epoch_ns("NULL")". In order to select one, please add explicit type casts. InternalError: Binder Error: Could not choose a best candidate function for the function call "epoch_ns(STRING_LITERAL)". In order to select one, please add explicit type casts. InternalError: Binder Error: No function matches the given name and argument types 'epoch_ns(INTEGER_LITERAL)'. You might need to add explicit type casts. ``` ## Examples The nanoseconds since 1970 of each event's timestamp and nanosecond timestamp. Only `tns` keeps the nanoseconds of row 1: ``` run(f"SELECT id, epoch_ns(ts), epoch_ns(tns) FROM {TABLE} ORDER BY id LIMIT 10") ``` ``` [(1, 1772320500000000000, 1772320500123456789), (2, 1772353845123456000, 1772353845123456000), (3, 1735560000000000000, 1735560000000000000), (4, None, None), (5, -1000, -1)] ``` The nanoseconds since midnight of each event's time, and since 1970 of its date: ``` run(f"SELECT id, epoch_ns(t), epoch_ns(d) FROM {TABLE} ORDER BY id LIMIT 10") ``` ``` [(1, 83700000000000, 1772236800000000000), (2, 30645123456000, 1772323200000000000), (3, 43200000000000, 1735516800000000000), (4, None, None), (5, 86399999999000, -86400000000000)] ``` Keep only the events after a Unix time in nanoseconds. This works, but [Make it faster](/develop/docs/dev-database-reference-sql-functions-date-time-epoch-ns#make-it-faster) has a faster way to write it: ``` run(f"SELECT id FROM {TABLE} WHERE epoch_ns(ts) > 1772300000000000000 ORDER BY id LIMIT 10") ``` ``` [(1,), (2,)] ``` ## How it runs in VAST The Query Engine runs on the cluster's CNodes, and a query on a table starts with a scan in VAST DataBase (`VAST_SCAN`). VAST DataBase can evaluate a comparison of a column with a constant, but not a function of a column, so `epoch_ns()` is always computed by the Query Engine: - **In the `SELECT` list,** the scan reads the column and the Query Engine computes `epoch_ns()` for each row it returns. - **In `WHERE`,** the scan sends the column for every row, and a `FILTER` step in the Query Engine computes `epoch_ns()` and keeps the rows that match. No rows are skipped in storage. The plan of the `WHERE` example shows the `FILTER` step above the scan: ``` plan(f"SELECT id FROM {TABLE} WHERE epoch_ns(ts) > 1772300000000000000") ``` ``` ┌───────────────────────────┐ │ PROJECTION │ │ ──────────────────── │ │ #1 │ │ │ └─────────────┬─────────────┘ ┌─────────────┴─────────────┐ │ FILTER │ │ ──────────────────── │ │ (epoch_ns(ts) > │ │ 1772300000000000000) │ │ │ └─────────────┬─────────────┘ ┌─────────────┴─────────────┐ │ VAST_SCAN │ │ ──────────────────── │ │ Function: VAST_SCAN │ │ │ │ Projections: │ │ ts │ │ id │ │ │ └───────────────────────────┘ ``` ## Make it faster - **Turn the number into a timestamp, not the column into a number.** On a `TIMESTAMP` column, `ts > make_timestamp(1772300000000000)` (the same time in microseconds) returns the same rows as `epoch_ns(ts) > 1772300000000000000`. The Query Engine computes the constant once, so the comparison of the raw column is pushed down to VAST DataBase, and the plan has no `FILTER` step: ``` plan(f"SELECT id FROM {TABLE} WHERE ts > make_timestamp(1772300000000000)") run(f"SELECT id FROM {TABLE} WHERE ts > make_timestamp(1772300000000000) ORDER BY id LIMIT 10") ``` ``` ┌───────────────────────────┐ │ VAST_SCAN │ │ ──────────────────── │ │ Function: VAST_SCAN │ │ Projections: id │ │ │ └───────────────────────────┘ [(1,), (2,)] ``` - **Use `epoch_ns()` in the `SELECT` list,** where it doesn't stop a filter from being pushed down. ## Limitations and errors - **About 1677 to 2262 only.** A timestamp or date outside that range fails with a `Conversion Error`: `Could not convert Timestamp(US) to Timestamp(NS` for a timestamp, `Could not convert DATE (...) to nanoseconds` for a date. Use [epoch_us](/develop/docs/dev-database-reference-sql-functions-date-time-epoch-us) for values outside it. - **No reverse form.** `epoch_ns(1772353845123456789)` fails with `No function matches the given name and argument types 'epoch_ns(INTEGER_LITERAL)'`. To turn nanoseconds into a timestamp, use [make_timestamp_ns](/develop/docs/dev-database-reference-sql-functions-date-time-make-timestamp-ns). - **One argument.** `epoch_ns(ts, ts)` fails with `No function matches the given name and argument types`. ``` run("SELECT epoch_ns(DATE '2300-01-01')") run("SELECT epoch_us(DATE '2300-01-01')") run("SELECT epoch_ns(1772353845123456789)") run("SELECT CAST(make_timestamp_ns(1772353845123456789) AS VARCHAR)") run(f"SELECT epoch_ns(ts, ts) FROM {TABLE} LIMIT 1") ``` ``` InternalError: Conversion Error: Could not convert DATE (2300-01-01) to nanoseconds [(10413792000000000,)] InternalError: Binder Error: No function matches the given name and argument types 'epoch_ns(INTEGER_LITERAL)'. You might need to add explicit type casts. [('2026-03-01 08:30:45.123456789',)] InternalError: Binder Error: No function matches the given name and argument types 'epoch_ns(TIMESTAMP, TIMESTAMP)'. You might need to add explicit type casts. ``` ## Similar functions | Function | Returns | Result for row 1's `tns`, `2026-02-28 23:15:00.123456789` (`epoch_ns` gives `1772320500123456789`) | | --- | --- | --- | | [epoch_us](/develop/docs/dev-database-reference-sql-functions-date-time-epoch-us) | Whole microseconds; the nanoseconds are dropped | `1772320500123456` | | [epoch_ms](/develop/docs/dev-database-reference-sql-functions-date-time-epoch-ms) | Whole milliseconds | `1772320500123` | | [epoch](/develop/docs/dev-database-reference-sql-functions-date-time-epoch) | Seconds, as a `DOUBLE` with the fraction to the microsecond | `1772320500.123456` | | [make_timestamp_ns](/develop/docs/dev-database-reference-sql-functions-date-time-make-timestamp-ns) | From nanoseconds to a `TIMESTAMP_NS`: the reverse of `epoch_ns` | (the reverse) | ``` run(f"SELECT epoch_ns(tns), epoch_us(tns), epoch_ms(tns), epoch(tns) FROM {TABLE} WHERE id = 1") ``` ``` [(1772320500123456789, 1772320500123456, 1772320500123, 1772320500.123456)] ``` Clean up: ``` run(f"DROP TABLE IF EXISTS {TABLE}") run(f"DROP SCHEMA IF EXISTS {SCHEMA}") conn.close() ``` ``` [] [] ``` ## See also - [epoch](/develop/docs/dev-database-reference-sql-functions-date-time-epoch), [epoch_ms](/develop/docs/dev-database-reference-sql-functions-date-time-epoch-ms) and [epoch_us](/develop/docs/dev-database-reference-sql-functions-date-time-epoch-us): seconds, milliseconds and microseconds. - [make_timestamp_ns](/develop/docs/dev-database-reference-sql-functions-date-time-make-timestamp-ns): from nanoseconds back to a timestamp. - [Date and time functions](/develop/docs/dev-database-reference-sql-functions-date-time): all the date and time functions. - [Where filters run](/develop/docs/dev-database-reference-sql-select#where-filters-run) and [pushdowns](/develop/docs/dev-database-reference-pushdowns). - [EXPLAIN](/develop/docs/dev-database-reference-sql-explain): how to read a plan.