DATEDIFF() in SQL Server

Examples of the DATEDIFF() Function

In this section, we will explore some examples of the DATEDIFF() function to better understand it.

Subtracting Two Dates and Getting the Result in Year Format

Code

SELECT DATEDIFF(year, '2022/08/03', '2023/08/05') AS ModifiedDate;

Output

1

Subtracting Two Dates and Getting the Result in Quarter Format

Code

SELECT DATEDIFF(quarter, '2022/08/03', '2023/08/05') AS ModifiedDate;

Output

4

Subtracting Two Dates and Getting the Result in Month Format

Code

SELECT DATEDIFF(month, '2022/08/03', '2023/08/05') AS ModifiedDate;

Output

12

Subtracting Two Dates and Getting the Result in Day Format

Code

SELECT DATEDIFF(day, '2022/08/03', '2023/08/05') AS ModifiedDate;

Output

367

Subtracting Two Dates and Getting the Result in Week Format

Code

SELECT DATEDIFF(week, '2022/08/03', '2023/08/05') AS ModifiedDate;

Output

52

Subtracting Two Dates and Getting the Result in Hour Format

Code

SELECT DATEDIFF(hour, '2022/08/03', '2023/08/05') AS ModifiedDate;

Output

8808

Subtracting Two Dates and Getting the Result in Minute Format

Code

SELECT DATEDIFF(minute, '2022/08/03', '2023/08/05') AS ModifiedDate;

Output

528480

Subtracting Two Dates and Getting the Result in Second Format

Code

SELECT DATEDIFF(second, '2022/08/03', '2023/08/05') AS ModifiedDate;

Output

31708800

Subtracting Two Dates and Getting the Result in Millisecond Format

Code

SELECT DATEDIFF(millisecond, '2023/08/03', '2023/08/05') AS ModifiedDate;

Output

172800000

Best Practices While Using DATEDIFF() function

Below are some tips which you should keep in mind while using the DATEDIFF() function in SQL:
 

• Choose the Correct Output Format - While choosing the format for storing the difference between data, we should carefully check if our selected type does not result in an overflow. For example, if we try to store a very large difference in seconds or milliseconds, it can result in an overflow error.
   
• Time Zones - Another important factor to keep in mind while using the DATEDIFF() function is to keep track of the time zones. Generally, we should keep all the entries in a standard timezone like UTC or GMT and convert it into other formats when required.
   
• Leap Years - We should also keep track of whether our date range covers any leap year to avoid any calculation mistakes and confusion.
   
• Efficient use - Although the DATEDIFF() function is a very useful function, we should ensure that we do not use it unnecessarily. Its unnecessary use can negatively affect the performance of the system.

Frequently Asked Questions

Can we use date and time together in the DATEDIFF() function?

Using the date and time together in the DATEDIFF() function is possible. We can provide more specific time values at the start and end date and calculate a more precise difference between them.

What are some alternatives to the DATEDIFF() function?

Some alternatives of the DATEDIFF() function include TIMESTAMPDIFF() function and TIMEDIFF() in SQL. Although these functions perform similarly to the DATEDIFF() function, they are less versatile than the DATEDIFF() function.

How does the DATEDIFF() function affect the performance of the query?

The effect of the DATEDIFF() function depends on the dataset's size and the query's complexity. If the dataset is too big or we use the DATEDIFF() function too often in the queries, it can negatively affect the query performance, making it slow and inefficient.

Conclusion

In this article, we discussed DATEDIFF() in SQL Server. We discussed the parameters and return type of the DATEDIFF() function. We also discussed some common examples of the DATEDIFF() function and their code implementations. In the end, we concluded by discussing some frequently asked questions.

So now that you know about DATEDIFF() in SQL Server, you can refer to similar articles.
 

• Sql functions
   
• SQL Introduction
   
• SQL Month() Function
   
• ROW_NUMBER FUNCTION in SQL
   

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