SQL Server DateTime vs DateTime2 Explained in Detail

Hello Dev, welcome to this comprehensive guide on SQL Server DateTime vs DateTime2. If you are a database developer or administrator, you must have come across these two data types while working with SQL Server. Both data types are used to store date and time values, but they have some differences in their respective features and functionalities.

What is SQL Server DateTime?

DateTime is a built-in data type in SQL Server that is used to store date and time values. The DateTime data type uses eight bytes of storage and can store dates within the range of January 1, 1753, to December 31, 9999.

Let’s take a closer look at the characteristics of DateTime.

1. Accuracy

The DateTime data type is accurate to a precision of three-hundredths of a second or 3.33 milliseconds. This level of accuracy is good enough for most applications.

2. Storage

As mentioned earlier, the DateTime data type in SQL Server uses eight bytes of storage. It stores both the date and time components in a single value.

3. Range

The range of values that can be stored in a DateTime data type is from January 1, 1753, to December 31, 9999.

4. Leap Year

The DateTime data type supports leap year calculations. However, there is a caveat. The year 1900 is not considered a leap year in SQL Server, although it is a leap year in the Gregorian calendar.

5. Time Zone

The DateTime data type does not store information about the time zone. It assumes that the datetime values are based on the server’s local time zone setting.

What is SQL Server DateTime2?

DateTime2 is a newer data type in SQL Server that was introduced in SQL Server 2008. It is an extension of the DateTime data type and provides higher precision and a larger range of values than DateTime.

Let’s take a closer look at the characteristics of DateTime2.

1. Accuracy

The DateTime2 data type is accurate to a precision of one-hundred nanoseconds or 0.0000001 seconds. This level of accuracy is much higher than that of the DateTime data type.

2. Storage

The DateTime2 data type uses between 6 and 8 bytes of storage, depending on the precision of the datetime value. It stores both the date and time components in a single value.

3. Range

The range of values that can be stored in a DateTime2 data type is from January 1, 0001, to December 31, 9999.

4. Leap Year

The DateTime2 data type supports leap year calculations. The year 1900 is considered a non-leap year in SQL Server, as it is in the Gregorian calendar.

5. Time Zone

The DateTime2 data type supports storage of information about the time zone. It provides a way to store datetime values in any time zone, including UTC.

Differences Between SQL Server DateTime and DateTime2

Now that we have seen the features and characteristics of both data types, let’s look at the differences between them.

1. Precision

The main difference between DateTime and DateTime2 is their precision. DateTime is accurate to a precision of three-hundredths of a second, while DateTime2 is accurate to a precision of one-hundred nanoseconds. This difference in precision can be important in certain applications where high precision is required.

2. Storage

DateTime2 uses between 6 and 8 bytes of storage, while DateTime uses 8 bytes of storage. This means that DateTime2 is more space-efficient than DateTime.

3. Range

DateTime2 can store values within a larger range than DateTime. DateTime can store values from January 1, 1753, to December 31, 9999, while DateTime2 can store values from January 1, 0001, to December 31, 9999.

4. Time Zone

DateTime2 supports storage of information about the time zone, while DateTime does not. This feature can be useful in applications where datetime values need to be stored and manipulated according to different time zones.

These are the main differences between SQL Server DateTime and DateTime2. Depending on your application’s requirements, you may need to use one or the other.

FAQs – Frequently Asked Questions

Q. What is the Maximum Size of DateTime and DateTime2 Data Types?

The maximum size of a DateTime data type is 8 bytes, while the maximum size of a DateTime2 data type depends on its precision. If the precision is 0 to 2, the maximum size is 6 bytes, if the precision is 3 to 4, the maximum size is 7 bytes, and if the precision is 5 to 7, the maximum size is 8 bytes.

Q. What is the Minimum and Maximum Value that can be Stored by DateTime and DateTime2 Data Types?

The minimum value that can be stored by a DateTime data type is January 1, 1753, and the maximum value is December 31, 9999. The minimum value that can be stored by a DateTime2 data type is January 1, 0001, and the maximum value is December 31, 9999.

Q. Which Data Type is More Accurate – DateTime or DateTime2?

DateTime2 is more accurate than DateTime. DateTime is accurate to a precision of three-hundredths of a second, while DateTime2 is accurate to a precision of one-hundred nanoseconds.

Q. Can DateTime2 Data Type Store Time Zone Information?

Yes, DateTime2 data type supports storage of information about the time zone. It provides a way to store datetime values in any time zone, including UTC.

Conclusion

In conclusion, SQL Server DateTime and DateTime2 are two data types that are used to store date and time values. Both data types have their own features, functionalities, and differences. Depending on your application’s requirements, you may need to use one or the other. We hope this guide has helped you understand the differences between SQL Server DateTime and DateTime2.