Convert SQL Server Date Format – A Comprehensive Guide for Dev

As a Dev, we all have come across situations where we need to convert a date from one format to another in SQL Server. It may seem like a trivial task, but it can be complex depending on the requirements. In this article, we’ll cover everything you need to know about converting date formats in SQL Server. Let’s get started!

What is a Date Format?

A date format is a string representation of a date that contains a combination of textual and numerical elements. For example, “dd/MM/yyyy” is a common date format that represents a date in the format of day/month/year. The format can vary depending on the culture and the requirement. In SQL Server, the date format is used to display or store the date in a specific format.

Understanding SQL Server Date Formats

SQL Server supports many date formats that can be used to display or store the date. The most common date format used in SQL Server is the “yyyy-MM-dd” format, which represents the date in the format of year-month-day. Here are some of the commonly used date formats in SQL Server:

Date Format	Description
yyyy-MM-dd	Year, Month, and Day
MM/dd/yyyy	Month, Day, and Year
dd/MM/yyyy	Day, Month, and Year
yyyy-MM-dd HH:mm:ss	Year, Month, Day, Hour, Minute, and Second

yyyy-MM-dd

The “yyyy-MM-dd” format is the ISO standard date format, and it is the most commonly used date format in SQL Server. It represents the date in the format of year-month-day. Here is an example:

SELECT CONVERT(VARCHAR(10), GETDATE(), 120) AS 'Date'

This query will return the current date in the “yyyy-MM-dd” format.

MM/dd/yyyy

The “MM/dd/yyyy” format represents the date in the format of month-day-year. Here is an example:

SELECT CONVERT(VARCHAR(10), GETDATE(), 101) AS 'Date'

This query will return the current date in the “MM/dd/yyyy” format.

dd/MM/yyyy

The “dd/MM/yyyy” format represents the date in the format of day-month-year. Here is an example:

SELECT CONVERT(VARCHAR(10), GETDATE(), 103) AS 'Date'

This query will return the current date in the “dd/MM/yyyy” format.

yyyy-MM-dd HH:mm:ss

The “yyyy-MM-dd HH:mm:ss” format represents the date and time in the format of year-month-day hour:minute:second. Here is an example:

SELECT CONVERT(VARCHAR(19), GETDATE(), 120) AS 'Date'

This query will return the current date and time in the “yyyy-MM-dd HH:mm:ss” format.

Converting SQL Server Date Formats

Now that we understand the various date formats in SQL Server, let’s look at how we can convert a date from one format to another. There are different ways to achieve this, and we’ll cover some of the most common methods.

Using the CONVERT Function

The CONVERT function is used to convert an expression from one datatype to another. We can use this function to convert a date from one format to another. Here is the syntax:

CONVERT(datatype, expression, style)

The datatype is the target datatype that we want to convert the expression to. In our case, it would be VARCHAR to convert the date to a string. The expression is the value that we want to convert, which is the date value. The style is the format code that we want to use to convert the date. Here is an example:

SELECT CONVERT(VARCHAR(10), GETDATE(), 101) AS 'Date'

This query will return the current date in the “MM/dd/yyyy” format.

Using the FORMAT Function

The FORMAT function is used to format a value with a specified format. We can use this function to format a date in a specific format. Here is the syntax:

FORMAT(expression, format)

The expression is the value that we want to format, which is the date value. The format is the format specifier that we want to use to format the date. Here is an example:

SELECT FORMAT(GETDATE(), 'MM/dd/yyyy') AS 'Date'

This query will return the current date in the “MM/dd/yyyy” format.

FAQ

Q. How do I convert a date to a different language?

A. To convert a date to a different language, we can use the SET LANGUAGE statement to set the language in which we want to display the date. Here is an example:

SET LANGUAGE 'French'SELECT CONVERT(VARCHAR(20), GETDATE(), 120) AS 'Date'

This query will return the current date in the “yyyy-MM-dd” format in French language.

Q. How do I convert a string to a date?

A. To convert a string to a date, we can use the CONVERT function with the style code that matches the format of the string. Here is an example:

SELECT CONVERT(DATE, '01/01/2021', 101) AS 'Date'

This query will convert the string “01/01/2021” to a date value in the “MM/dd/yyyy” format.

Q. How do I check the default date format in SQL Server?

A. To check the default date format in SQL Server, we can use the @@DATEFORMAT global variable. Here is an example:

SELECT @@DATEFORMAT AS 'Date Format'

This query will return the default date format of the SQL Server instance.

Q. How do I set the default date format in SQL Server?

A. To set the default date format in SQL Server, we can use the SET DATEFORMAT statement. Here is an example:

SET DATEFORMAT 'MDY'

This statement will set the default date format to the “MM/dd/yyyy” format.

Conclusion

Converting SQL Server date formats may seem like a small task, but it can be crucial in some applications. We covered the most commonly used date formats in SQL Server and how to convert them using different methods. We also covered some frequently asked questions related to converting date formats. We hope this article was helpful, and you can use this knowledge to make your application more robust.