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smalldatetime (Transact-SQL)

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Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL database in Microsoft Fabric

Defines a date that is combined with a time of day. The time is based on a 24-hour day, with seconds always zero (:00) and without fractional seconds.

Note

Use the time, date, datetime2, and datetimeoffset data types for new work. These types align with the SQL standard, as they're more portable. time, datetime2 and datetimeoffset provide more seconds precision. datetimeoffset provides time zone support for globally deployed applications.

smalldatetime description

Property Value
Syntax smalldatetime
Usage DECLARE @MySmallDateTime SMALLDATETIME;

CREATE TABLE Table1 (Column1 SMALLDATETIME);
Default string literal formats
(used for down-level client)		 Not applicable
Date range 1900-01-01 through 2079-06-06

January 1, 1900, through June 6, 2079
Time range 00:00:00 through 23:59:59

2024-05-09 23:59:59 rounds to 2024-05-10 00:00:00
Element ranges yyyy is four digits, ranging from 1900 to 2079, which represents a year.

MM is two digits, ranging from 01 to 12, which represents a month in the specified year.

dd is two digits, ranging from 01 to 31 depending on the month, which represents a day of the specified month.

HH is two digits, ranging from 00 to 23, which represents the hour.

mm is two digits, ranging from 00 to 59, that represents the minute.

ss is two digits, ranging from 00 to 59, that represents the second. Values that are 29.998 seconds or less are rounded down to the nearest minute. Values of 29.999 seconds or more are rounded up to the nearest minute.
Character length 19 positions maximum
Storage size 4 bytes, fixed
Accuracy One minute
Default value 1900-01-01 00:00:00
Calendar Gregorian

(Doesn't include the complete range of years.)
User-defined fractional second precision No
Time zone offset aware and preservation No
Daylight saving aware No

ANSI and ISO 8601 compliance

smalldatetime isn't ANSI or ISO 8601 compliant.

Convert date and time data

When you convert to date and time data types, SQL Server rejects all values it can't recognize as dates or times. For information about using the CAST and CONVERT functions with date and time data, see CAST and CONVERT.

Convert smalldatetime to other date and time types

This section describes what occurs when a smalldatetime data type is converted to other date and time data types.

For a conversion to date, the year, month, and day are copied. The following code shows the results of converting a smalldatetime value to a date value.

DECLARE @smalldatetime AS SMALLDATETIME = '1955-12-13 12:43:10';

DECLARE @date AS DATE = @smalldatetime;

SELECT @smalldatetime AS '@smalldatetime',
       @date AS 'date';

Here's the result set.

@smalldatetime        date
--------------------- ----------
1955-12-13 12:43:00   1955-12-13

When the conversion is to time(n), the hours, minutes, and seconds are copied. The fractional seconds are set to 0. The following code shows the results of converting a smalldatetime value to a time(4) value.

DECLARE @smalldatetime AS SMALLDATETIME = '1955-12-13 12:43:10';

DECLARE @time AS TIME (4) = @smalldatetime;

SELECT @smalldatetime AS '@smalldatetime',
       @time AS 'time';

Here's the result set.

@smalldatetime          time
----------------------- -------------
1955-12-13 12:43:00     12:43:00.0000

When the conversion is to datetime, the smalldatetime value is copied to the datetime value. The fractional seconds are set to 0. The following code shows the results of converting a smalldatetime value to a datetime value.

DECLARE @smalldatetime AS SMALLDATETIME = '1955-12-13 12:43:10';

DECLARE @datetime AS DATETIME = @smalldatetime;

SELECT @smalldatetime AS '@smalldatetime',
       @datetime AS 'datetime';

Here's the result set.

@smalldatetime          datetime
----------------------- -----------------------
1955-12-13 12:43:00     1955-12-13 12:43:00.000

For a conversion to datetimeoffset(n), the smalldatetime value is copied to the datetimeoffset(n) value. The fractional seconds are set to 0, and the time zone offset is set to +00:0. The following code shows the results of converting a smalldatetime value to a datetimeoffset(4) value.

DECLARE @smalldatetime AS SMALLDATETIME = '1955-12-13 12:43:10';

DECLARE @datetimeoffset AS DATETIMEOFFSET (4) = @smalldatetime;

SELECT @smalldatetime AS '@smalldatetime',
       @datetimeoffset AS 'datetimeoffset(4)';

Here's the result set.

@smalldatetime        datetimeoffset(4)
--------------------- ------------------------------
1955-12-13 12:43:00   1955-12-13 12:43:00.0000 +00:0

For the conversion to datetime2(n), the smalldatetime value is copied to the datetime2(n) value. The fractional seconds are set to 0. The following code shows the results of converting a smalldatetime value to a datetime2(4) value.

DECLARE @smalldatetime AS SMALLDATETIME = '1955-12-13 12:43:10';

DECLARE @datetime2 AS DATETIME2 (4) = @smalldatetime;

SELECT @smalldatetime AS '@smalldatetime',
       @datetime2 AS ' datetime2(4)';

Here's the result set.

@smalldatetime        datetime2(4)
--------------------- ------------------------
1955-12-13 12:43:00   1955-12-13 12:43:00.0000

Examples

A. Cast string literals with seconds to smalldatetime

The following example compares the conversion of seconds in string literals to smalldatetime.

SELECT CAST ('2024-05-08 12:35:29' AS SMALLDATETIME),
       CAST ('2024-05-08 12:35:30' AS SMALLDATETIME),
       CAST ('2024-05-08 12:59:59.998' AS SMALLDATETIME);
Input Output
2024-05-08 12:35:29 2024-05-08 12:35:00
2024-05-08 12:35:30 2024-05-08 12:36:00
2024-05-08 12:59:59.998 2024-05-08 13:00:00

B. Compare date and time data types

The following example compares the results of casting a string to each date and time data type.

SELECT CAST ('2024-05-08 12:35:29.1234567 +12:15' AS TIME (7)) AS 'time',
       CAST ('2024-05-08 12:35:29.1234567 +12:15' AS DATE) AS 'date',
       CAST ('2024-05-08 12:35:29.123' AS SMALLDATETIME) AS 'smalldatetime',
       CAST ('2024-05-08 12:35:29.123' AS DATETIME) AS 'datetime',
       CAST ('2024-05-08 12:35:29.1234567 +12:15' AS DATETIME2 (7)) AS 'datetime2',
       CAST ('2024-05-08 12:35:29.1234567 +12:15' AS DATETIMEOFFSET (7)) AS 'datetimeoffset';
Data type Output
time 12:35:29.1234567
date 2024-05-08
smalldatetime 2024-05-08 12:35:00
datetime 2024-05-08 12:35:29.123
datetime2 2024-05-08 12:35:29.1234567
datetimeoffset 2024-05-08 12:35:29.1234567 +12:15

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