Interval literal

A literal that represents a time span.

1: Interval subtype units
2: Interval qualifier

A literal that represents a time span.

Syntax

[ @ ] [-] { quantity subtype-unit }[...] [ AGO ]

Parameters

@: Ignored
- (minus): Specifies a negative interval value.
quantity: Integer numeric constant
[subtype-unit](/en/sql-reference/language-elements/literals/datetime-literals/interval-literal/interval-subtype-units/): See Interval subtype units for valid values. Subtype units must be specified for year-month intervals; they are optional for day-time intervals.
AGO: Specifies a negative interval value. AGO and - (minus) are synonymous.

Notes

The amounts of different units are implicitly added up with appropriate sign accounting.
The boundaries of an interval constant are:
- 9223372036854775807 usec to -9223372036854775807 usec
- 296533 years 3 mons 21 days 04:00:54.775807 to -296533 years -3 mons -21 days -04:00:54.775807
The range of an interval constant is +/– 2⁶³ – 1 microseconds.
In Vertica, interval fields are additive and accept large floating-point numbers.

Examples

See Specifying interval input.

1 - Interval subtype units

The following tables lists subtype units that you can specify in an interval literal, divided into major categories:.

The following tables lists subtype units that you can specify in an interval literal, divided into major categories:

Year-month subtype units
Day-time subtype units

Year-month subtype units

Subtypes	Units	Notes
Millennium	`mil`, `millennium`, `millennia`, `mils`, `millenniums`
Century	`c`, `cent`, `century`, `centuries`
Decade	`dec`, `decs`, `decade`, `decades`
Year	`a`	Julian year: 365.25 days
	`ka`	Julian kilo-year: 365250 days
	`y`, `yr`, `yrs`, `year`, `years`	Calendar year: 365 days
Quarter	`q`, `qtr`, `qtrs`, `quarter`, `quarters`
Month	`m`, `mon`, `mons`, `months`, `month`	Vertica can interpret `m` as minute or month, depending on context. See Processing m Input below.
Week	`w`, `wk`, `week`, `wks`, `weeks`

Day-time subtype units

Subtypes	Units	Notes
Day	`d`, `day`, `days`
Hour	`h`, `hr`, `hrs`, `hour`, `hours`
Minute	`m`, `min`, `mins`, `minute`, `minutes`	Vertica can interpret input unit `m` as minute or month, depending on context. See Processing m Input below.
Second	`s`, `sec`, `secs`, `second`, `seconds`
Millisecond	`ms`, `msec`, `msecs`, `msecond`, `mseconds`, `millisecond`, `milliseconds`
Microsecond	`us`, `usec`, `usecs`, `usecond`, `useconds`, `microseconds`, `microsecond`

Processing m input

Vertica uses context to interpret the input unit m as months or minutes. For example, the following command creates a one-column table with an interval value:

=> CREATE TABLE int_test(i INTERVAL YEAR TO MONTH);

Given the following INSERT statement, Vertica interprets the interval literal 1y 6m as 1 year 6 months:

=> INSERT INTO int_test VALUES('1y 6m');
 OUTPUT
--------
      1
(1 row)
=> COMMIT;
COMMIT
=> SET INTERVALSTYLE TO UNITS;
SET
=> SELECT * FROM int_test;
        i
-----------------
 1 year 6 months
(1 row)

Tip

The SET INTERVALSTYLE statement changes interval output to include subtype unit identifiers. For details, see Setting interval unit display.

The following ALTER TABLE statement adds a DAY TO MINUTE interval column to table int_test:

=>  ALTER TABLE int_test ADD COLUMN x INTERVAL DAY TO MINUTE;
ALTER TABLE

The next INSERT statement sets the first and second columns to 3y 20m and 1y 6m, respectively. In this case, Vertica interprets the m input literals in two ways:

For column i, Vertica interprets the m input as months, and displays 4 years 8 months.
For column x, Vertica interprets the m input as minutes. Because the interval is defined as DAY TO MINUTE, it converts the inserted input value 1y 6m to 365 days 6 minutes:

=> INSERT INTO int_test VALUES ('3y 20m', '1y 6m');
 OUTPUT
--------
      1
(1 row)

=> SELECT * FROM int_test;
        i         |        x
------------------+-----------------
 1 year 6 months  |
 4 years 8 months | 365 days 6 mins
(2 rows)

2 - Interval qualifier

Specifies how to interpret and format an interval literal for output, and optionally sets precision.

Specifies how to interpret and format an interval literal for output, and optionally sets precision. Interval qualifiers are composed of one or two units:

unit [ TO unit ] [ (p) ]

where:

unit specifies a day-time or year-month subtype.
p specifies precision, an integer between 0 and 6.
Note

Precision only applies to SECOND units, specifying the number of decimal digits to show after the seconds value decimal point. The default precision for SECOND is 6.

When SECOND is the second unit of a qualifier—for example, DAY TO SECOND or MINUTE TO SECOND—it has a precision of 2 places before the decimal point.

For example:
```
=> SELECT INTERVAL '6 122.538987' MINUTE TO SECOND (5);
  ?column?
-------------
 08:02.53899
(1 row)
```
For details, see Specifying interval precision.

If an interval omits an interval qualifier, the default is DAY TO SECOND(6).

Interval qualifiers are divided into two categories:

day-time
year-month

Day-time interval qualifiers

Qualifier	Description
`DAY`	Unconstrained
`DAY TO HOUR`	Span of days and hours
`DAY TO MINUTE`	Span of days and minutes
`DAY TO SECOND [(``p``)]`	Span of days, hours, minutes, seconds, and fractions of a second.
`HOUR`	Hours within days
`HOUR TO MINUTE`	Span of hours and minutes
`HOUR TO SECOND [(``p``)]`	Span of hours and seconds
`MINUTE`	Minutes within hours
`MINUTE TO SECOND [(``p``)]`	Span of minutes and seconds
`SECOND [(``p``)]`	Seconds within minutes

Year-month interval qualifiers

YEAR: Unconstrained
MONTH: Months within year
YEAR TO MONTH: Span of years and months

Note

Vertica also supports INTERVALYM, which is an alias for INTERVAL YEAR TO MONTH. Thus, the following two statements are equivalent:

=> SELECT INTERVALYM '1 2';
 ?column?
----------
 1-2
(1 row)
=> SELECT INTERVAL '1 2' YEAR TO MONTH;
?column?
----------
1-2
(1 row)

Examples

See Controlling interval format.