CODEWITHSUNDEEP
mysqlunix-timestamp
why.you.and.i
why.you.and.i

Reputation: 507

How to convert UNIX time before 1970 to date format in MySQL?

I have a database using unix time for its dates ( i am using mySQL). I want to retrieve the dates in daily date format. This is my query:

SELECT FROM_UNIXTIME(time_created) FROM member

This works fine with dates after 1970 (for example, 1314162229) but doesn't work for dates before 1970 (for example, -769338000). Is there any work around here?

Upvotes: 10

Views: 9751

Answers (4)

Manasse
Manasse

Reputation: 160

I found a new way:

converting to MySQL date:

SELECT DATE_ADD(FROM_UNIXTIME(0), interval YOURTIMESTAMPHERE second);

converting your epoch to a date string:

SELECT DATE_FORMAT(DATE_ADD(FROM_UNIXTIME(0), interval YOURTIMESTAMPHERE second), '%Y-%m-%d');

And back

SELECT TIMESTAMPDIFF(second,FROM_UNIXTIME(0),'1960-01-01 00:00:00' );

source: http://www.epochconverter.com/programming/mysql-from-unixtime.php#negavtiveEpoch

Upvotes: 9

Braulio J. Solano
Braulio J. Solano

Reputation: 161

SELECT DATE_ADD(CAST('1970-01-01 00:00:00' AS DATETIME), INTERVAL `time_created` SECOND) FROM `member`

Upvotes: 0

glglgl
glglgl

Reputation: 91059

A possible workaround would be to have a constant handy corresponding to the seconds in a certain number of years (preferrably a multiple of 4). You could add this constant, translate the time and then subtract the number of years chosen.

Example: choose 40 years.

Determine the constant:

MySQL [files]> select adddate(from_unixtime(0), interval 40 year);
+---------------------------------------------+
| adddate(from_unixtime(0), interval 40 year) |
+---------------------------------------------+
| 2010-01-01 01:00:00                         |
+---------------------------------------------+
1 row in set (0.09 sec)

MySQL [files]> select unix_timestamp(adddate(from_unixtime(0), interval 40 year));
+-------------------------------------------------------------+
| unix_timestamp(adddate(from_unixtime(0), interval 40 year)) |
+-------------------------------------------------------------+
|                                                  1262304000 |
+-------------------------------------------------------------+
1 row in set (0.09 sec)

Now you can every unix timestamp x between 1930 and 20xx and use it.

select subdate(from_unixtime(x+1262304000), interval 40 year);

With your example -769338000, you get

MySQL [files]> select subdate(from_unixtime(-769338000+1262304000), interval 40 year);
+-----------------------------------------------------------------+
| subdate(from_unixtime(-769338000+1262304000), interval 40 year) |
+-----------------------------------------------------------------+
| 1945-08-15 17:00:00                                             |
+-----------------------------------------------------------------+
1 row in set (0.09 sec)

Upvotes: 10

Peter Rowell
Peter Rowell

Reputation: 17713

To my knowledge there is no such thing as UNIX time prior to 1/1/1970 00:00 UTC. More at Wikipedia.

Upvotes: -3

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