Mastering SQL Date Types: Best Practices and Examples

Working with dates in SQL can be tricky. Each DBMS implements DATE, TIME, DATETIME, and TIMESTAMP slightly differently, often leading to subtle bugs in multi-region applications.

This guide outlines these types for MySQL, PostgreSQL, SQL Server, and Oracle. It shares examples and best practices to help developers choose the right type for the right job.

SQL Date Data Types

MySQL

• DATE: Calendar date only.

• DATETIME: Date and time, no timezone.

• TIMESTAMP: UTC storage with timezone conversion.

    SELECT CURRENT_TIMESTAMP;
  

PostgreSQL

• TIMESTAMP WITH TIME ZONE: For global systems.

• INTERVAL: Duration between timestamps.

    SELECT AGE('2025-07-21', '2024-07-21');
  

SQL Server

• DATETIMEOFFSET: Includes timezone offsets.

Oracle

• TIMESTAMP WITH LOCAL TIME ZONE: Adjusts for session timezone.

Best Practices

1. Normalize timestamps to UTC.

2. Use timezone-aware types for multi-region systems.

3. Index frequently queried date columns.

4. Avoid storing dates as strings.

5. Validate input ranges at the DB level.

FAQ

How to extract date from datetime?

MySQL: DATE(datetime_column)

SQL Server: CAST(datetime_column AS DATE)

How to get today’s date?

SELECT CURRENT_DATE;

Is BETWEEN reliable for dates?

Yes, if dates are consistently formatted.

How to format SQL dates?

PostgreSQL: TO_CHAR(date_column, 'YYYY-MM-DD')

Conclusion

SQL date types are not one-size-fits-all. Choosing the correct type and applying best practices helps keep your data accurate and your queries fast. For a deeper exploration—including functions, timezone nuances, and advanced examples—read the full SQL Date Data Types guide.