What are Differences Between SQL Server DATE and DATETIME types?

The DATE and DATETIME data types in SQL Server are both used to store date related information, but they serve slightly different purposes and have distinct behavior. Here’s how they compare:

📅 DATE vs DATETIME

Feature	DATE	DATETIME
Stores	Only the date ie., year, month and day	Date and Time (down to miliseconds)
Default Format	'YYYY-MM-DD'	'YYYY-MM-DD hh:mm:ss'
Time Component	Set to Midnight 00:00:00	Captures full time (up to 3 milliseconds precision)
Range	0001-01-01 through 9999-12-31	1753-01-01 through 9999-12-31
Storage Size	3 bytes	8 bytes
Performance	Faster indexing and querying	Slightly heavier due to time calculations
Use Cases	Birthdays, due dates, holidays etc.	Timestamps, logs, audit trails etc.
Conversion Friendly	Easier to format and compare	Requires formatting functions for user facing data

Example:

-- DATE type
DECLARE @dateOnly DATE = '2025-07-12';

-- DATETIME type
DECLARE @dateTimeFull DATETIME = '2025-07-12 14:35:00';

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