Is there a MySQL function which can be used to convert a Unix timestamp into a human readable date? I have one field where I save Unix times and now I want to add another field for human readable dates.

Use FROM_UNIXTIME():

SELECT
  FROM_UNIXTIME(timestamp) 
FROM 
  your_table;

See also: MySQL documentation on FROM_UNIXTIME().

What’s missing from the other answers (as of this writing) and not directly obvious is that from_unixtime can take a second parameter to specify the format like so:

SELECT
  from_unixtime(timestamp, '%Y %D %M %H:%i:%s')
FROM 
  your_table

I think what you’re looking for is FROM_UNIXTIME()

Need a unix timestamp in a specific timezone?

Here’s a one liner if you have quick access to the mysql cli:

mysql> select convert_tz(from_unixtime(1467095851), 'UTC', 'MST') as 'local time';

+---------------------+
| local time          |
+---------------------+
| 2016-06-27 23:37:31 |
+---------------------+

Replace 'MST' with your desired timezone. I live in Arizona 🌵 thus the conversion from UTC to MST.

Why bother saving the field as readable? Just us AS

SELECT theTimeStamp, FROM_UNIXTIME(theTimeStamp) AS readableDate
               FROM theTable
               WHERE theTable.theField = theValue;

EDIT: Sorry, we store everything in milliseconds not seconds. Fixed it.

You can use the DATE_FORMAT function. Here‘s a page with examples, and the patterns you can use to select different date components.

Easy and simple way:

select from_unixtime(column_name, '%Y-%m-%d') from table_name

Since I found this question not being aware, that mysql always stores time in timestamp fields in UTC but will display (e.g. phpmyadmin) in local time zone I would like to add my findings.

I have an automatically updated last_modified field, defined as:

`last_modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP

Looking at it with phpmyadmin, it looks like it is in local time, internally it is UTC

SET time_zone = '+04:00'; // or '+00:00' to display dates in UTC or 'UTC' if time zones are installed.
SELECT last_modified, UNIX_TIMESTAMP(last_modified), from_unixtime(UNIX_TIMESTAMP(last_modified), '%Y-%c-%d %H:%i:%s'), CONVERT_TZ(last_modified,@@session.time_zone,'+00:00') as UTC FROM `table_name`

In any constellation, UNIX_TIMESTAMP and ‘as UTC’ are always displayed in UTC time.

Run this twice, first without setting the time_zone.