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Timestamp Types

Timestamps represent points in absolute time, usually called instants. DuckDB represents instants as the number of microseconds (µs) since 1970-01-01 00:00:00+00.

Timestamp Types

Name Aliases Description
TIMESTAMP_NS TIMESTAMP, DATETIME timestamp with nanosecond precision (ignores time zone)
TIMESTAMP_MS   timestamp with millisecond precision (ignores time zone)
TIMESTAMP_S   timestamp with second precision (ignores time zone)
TIMESTAMPTZ TIMESTAMP WITH TIME ZONE timestamp (uses time zone)

A timestamp specifies a combination of DATE (year, month, day) and a TIME (hour, minute, second, microsecond). Timestamps can be created using the TIMESTAMP keyword, where the data must be formatted according to the ISO 8601 format (YYYY-MM-DD hh:mm:ss[.zzzzzz][+-TT[:tt]]).

SELECT TIMESTAMP_NS '1992-09-20 11:30:00.123456'; -- 1992-09-20 11:30:00.123456
SELECT TIMESTAMP    '1992-09-20 11:30:00.123456'; -- 1992-09-20 11:30:00.123456
SELECT DATETIME     '1992-09-20 11:30:00.123456'; -- 1992-09-20 11:30:00.123456
SELECT TIMESTAMP_MS '1992-09-20 11:30:00.123456'; -- 1992-09-20 11:30:00.123
SELECT TIMESTAMP_S  '1992-09-20 11:30:00.123456'; -- 1992-09-20 11:30:00
SELECT TIMESTAMPTZ  '1992-09-20 11:30:00.123456'; -- 1992-09-20 11:30:00.123456+00
SELECT TIMESTAMP WITH TIME ZONE '1992-09-20 11:30:00.123456';
-- 1992-09-20 11:30:00.123456+00

Special Values

There are also three special date values that can be used on input:

Input string Valid types Description
epoch TIMESTAMP, TIMESTAMPTZ 1970-01-01 00:00:00+00 (Unix system time zero)
infinity TIMESTAMP, TIMESTAMPTZ later than all other time stamps
-infinity TIMESTAMP, TIMESTAMPTZ earlier than all other time stamps

The values infinity and -infinity are specially represented inside the system and will be displayed unchanged; but epoch is simply a notational shorthand that will be converted to the time stamp value when read.

SELECT '-infinity'::TIMESTAMP, 'epoch'::TIMESTAMP, 'infinity'::TIMESTAMP;
Negative Epoch Positive
-infinity 1970-01-01 00:00:00 infinity

Functions

See Timestamp Functions.

Time Zones

The TIMESTAMPTZ type can be binned into calendar and clock bins using a suitable extension. The built-in ICU extension implements all the binning and arithmetic functions using the International Components for Unicode time zone and calendar functions.

To set the time zone to use, first load the ICU extension. The ICU extension comes pre-bundled with several DuckDB clients (including Python, R, JDBC, and ODBC), so this step can be skipped in those cases. In other cases you might first need to install and load the ICU extension.

INSTALL icu;
LOAD icu;

Next, use the SET TimeZone command:

SET TimeZone = 'America/Los_Angeles';

Time binning operations for TIMESTAMPTZ will then be implemented using the given time zone.

A list of available time zones can be pulled from the pg_timezone_names() table function:

SELECT 
    name,
    abbrev,
    utc_offset 
FROM pg_timezone_names() 
ORDER BY 
    name;

You can also find a reference table of available time zones.

Calendars

The ICU extension also supports non-Gregorian calendars using the SET Calendar command. Note that the INSTALL and LOAD steps are only required if the DuckDB client does not bundle the ICU extension.

INSTALL icu;
LOAD icu;
SET Calendar = 'japanese';

Time binning operations for TIMESTAMPTZ will then be implemented using the given calendar. In this example, the era part will now report the Japanese imperial era number.

A list of available calendars can be pulled from the icu_calendar_names() table function:

SELECT name
FROM icu_calendar_names()
ORDER BY 1;

Settings

The current value of the TimeZone and Calendar settings are determined by ICU when it starts up. They can be queried from in the duckdb_settings() table function:

SELECT *
FROM duckdb_settings()
WHERE name = 'TimeZone';
┌──────────┬──────────────────┬───────────────────────┬────────────┐
│   name   │      value       │      description      │ input_type │
│ varchar  │     varchar      │        varchar        │  varchar   │
├──────────┼──────────────────┼───────────────────────┼────────────┤
│ TimeZone │ Europe/Amsterdam │ The current time zone │ VARCHAR    │
└──────────┴──────────────────┴───────────────────────┴────────────┘
SELECT *
FROM duckdb_settings()
WHERE name = 'Calendar';
┌──────────┬───────────┬──────────────────────┬────────────┐
│   name   │   value   │     description      │ input_type │
│ varchar  │  varchar  │       varchar        │  varchar   │
├──────────┼───────────┼──────────────────────┼────────────┤
│ Calendar │ gregorian │ The current calendar │ VARCHAR    │
└──────────┴───────────┴──────────────────────┴────────────┘
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Last modified: 2024-03-02