Timestamp vs Datetime in MySQL: Key Differences and Usage

In MySQL, TIMESTAMP stores date and time values as UTC and converts them to the current timezone on retrieval, while DATETIME stores date and time as-is without timezone conversion. TIMESTAMP has a smaller range but automatic timezone handling, whereas DATETIME supports a wider date range but no timezone awareness.

Quick Comparison

Here is a quick side-by-side comparison of TIMESTAMP and DATETIME in MySQL.

Feature	TIMESTAMP	DATETIME
Storage Size	4 bytes	8 bytes
Date Range	1970-01-01 00:00:01 UTC to 2038-01-19 03:14:07 UTC	1000-01-01 00:00:00 to 9999-12-31 23:59:59
Timezone Handling	Stores in UTC, converts on retrieval	No timezone conversion, stores literal value
Automatic Initialization/Update	Supports automatic current timestamp	Supports automatic current timestamp (MySQL 5.6.5+), but less common
Use Case	Ideal for recording event times with timezone awareness	Ideal for storing absolute date/time values without timezone

Key Differences

TIMESTAMP stores the number of seconds since the Unix epoch (1970-01-01 00:00:00 UTC). It automatically converts stored values from the current time zone to UTC for storage, and back from UTC to the current time zone when retrieved. This makes it useful for tracking events in a timezone-aware manner.

In contrast, DATETIME stores the date and time as a literal value without any timezone conversion. It uses more storage space and supports a much wider range of dates, from year 1000 to 9999. This makes it suitable for storing fixed dates and times that should not change with timezone shifts, like birthdays or scheduled appointments.

Another difference is the automatic initialization and update behavior. TIMESTAMP columns can automatically set to the current timestamp on insert or update by default. DATETIME gained similar support in MySQL 5.6.5 and later, but it is less commonly used for this purpose.

Code Comparison

mysql

CREATE TABLE events_timestamp (
  id INT AUTO_INCREMENT PRIMARY KEY,
  event_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

INSERT INTO events_timestamp () VALUES ();

SELECT id, event_time FROM events_timestamp;

Output

id | event_time
1  | 2024-06-01 12:00:00

DATETIME Equivalent

mysql

CREATE TABLE events_datetime (
  id INT AUTO_INCREMENT PRIMARY KEY,
  event_time DATETIME DEFAULT CURRENT_TIMESTAMP
);

INSERT INTO events_datetime () VALUES ();

SELECT id, event_time FROM events_datetime;

Output

id | event_time
1  | 2024-06-01 12:00:00

When to Use Which

Choose TIMESTAMP when you need to track moments in time that should adjust according to the user's or server's timezone, such as logging events or recording last update times. It is efficient and handles timezone conversions automatically.

Choose DATETIME when you need to store fixed date and time values that do not change with timezone, like birthdays, deadlines, or scheduled events. It supports a wider date range and stores the exact value you provide.

Key Takeaways

TIMESTAMP stores UTC-based times with automatic timezone conversion on retrieval.

DATETIME stores literal date and time values without timezone adjustments.

TIMESTAMP uses less storage but has a limited date range (1970 to 2038).

DATETIME supports a wider date range (1000 to 9999) but uses more storage.

Use TIMESTAMP for timezone-aware event tracking and DATETIME for fixed date/time storage.