So I have this app that receives packages from cell phones including gps time which is UTC. I store this in my mysql database from php currently.
I have two datetime fields one which contains the time from the phone and one which is the servers time.
my query looks like this: INSERT INTO GeoLocation(Time, ServerTime) VALUES(FROM_UNIXTIME(1353438497), UTC_TIMESTAMP())
I simplified and removed all other values. The current utc unix timestamp is right now: 1353438597 accordnign to http://www.unixtimestamp.com/index.php so my other cellphone timestamp is 100 seconds old, makes perfect sense.
now however to the funny thing. I should mention i live in Sweden with +1 timezone and the server is in sweden to, most likely configured to swedish time
when i use phpmyadmin to view the values just inserted it says that Time is 2012-11-20 20:08:17 but server time is 2012-11-20 19:08:23. So even tho both were correct utc times, one entered ass From_unixtime and the other with UTC_TIMESTAMP they now show different time.
I read you needed to set the timezone with SET time_zone = '+00:00';
so I tried to open a query window in phpmyadmin and entered
SET time_zone = '+00:00';
SELECT Time, ServerTime FROM `GeoLocation` WHERE 1;
but i still get the exact same times reported for both fields.
however phpmyadmin does run both rows because if i instead try this:
SELECT # #global.time_zone , # #session.time_zone
I get this:
##global.time_zone ##session.time_zone
SYSTEM SYSTEM
but if I do this:
SET time_zone = '+00:00';
SELECT ##global.time_zone, ##session.time_zone
I get this:
##global.time_zone ##session.time_zone
SYSTEM +00:00
So it doesn't make any sense to me, I have confirmed I feed it UTC time (from unix time) and yet it displays it as UTC+1 and it does not help to set time zone.
Any ideas?
The solution is to execute "SET time_zone = '+00:00';" before STORING data in the database (insert).
It will do you no good when you read the data, but if you call it when you store the data everything will be fine.
Related
I have a table named "students" where student information are stored. Last week, I added a column (type-datetime) to keep track students last login time.
It was working well when testing with localhost. So, I uploaded to hosting and after a few days, I noticed datetime are different with my local times. I called now() function in my code and it is inserting with server time (Seattle,USA Time). I tried to set it with my timezone.
SELECT ##session.time_zone;
SET time_zone = 'Asia/Rangoon';
SET time_zone = "+06:30";
SET ##session.time_zone = "+06:30";
although it is executed, it don't affect and inserting with server time like before.
My Question is how should I update my existing datetime value column to my respective timezone. Thanks and appreciating.
The best approach imho is to save all dates in UTC. Only at presentation time these times should be converted to the time and zone for the user.
Because you are using PHP, you can convert input into UTC and convert output to the desired timezone for presentation.
This makes it also easy and possible to show foreign visitors their own time on your website.
When exporting a file through phpMyAdmin some timestamps are put back an hour. How may I prevent this? I do not want timestamps tampered with. Here's a screenshot for the curious (see the dates.)
I believe the cause may be the SET time_zone = "+00:00"; that is added to every export file.
Is this suppose to happen? Is it a known bug?
I'm running:
-- Server version: 5.5.37-0ubuntu0.14.04.1
-- PHP Version: 5.5.9-1ubuntu4
The times are not actually being 'tampered with'.
MySQL interally stores TIMESTAMP columns converted to UTC time, then uses a mixture of system and session (client session) values to determine what to display to the user.
You can check both of these values running the following query yourself.
SELECT ##global.time_zone, ##session.time_zone;
So when your PHPMA script generates its dump, its specifying a session time_zone variable so when you run it MySQL will convert them all from that timezone back to UTC. When you then go to import that to another database, it will still convert them back to the UTC values you're expecting.
So to summarise if the values in the dump with SET time_zone = "+00:00"; are all "1 hour behind" the values you see when querying via PHPMyAdmin, this only appears this way because the connection via PHPMyAdmin will have it's timezone one hour ahead of UTC.
I'm working on a shared hosting so I don't have access to mysql configuration files.
The default timezone on that system is 'America/New_York' but I need to use UTC -5:00 for my databases.
Everytime I perform a query the timezone is set to UTC -5:00 like this:
SET time_zone='-5:00';
If I want the current time, SELECT NOW() returns the correct time and date, but when updating a table mysql uses the SYSTEM time and not the set timezone
UPDATE administradores SET ultimo_acceso=NOW() WHERE id=1
Why does those values are different? Shouldn't be the same time in both queries since I'm overriding the timezone?
I also tried with INSERT statement and that works fine.
If the ultimo_acceso field is of type TIMESTAMP, then the value is actually being stored as UTC and then converted back to the current time zone when you select the value back out. So you need to set the time zone again in the select statement.
If you are using a DATETIME data type, then the value you set should be persisted without conversion and you will get back exactly what you store - regardless of the timezone setting at time of select.
See the MySQL docs on this subject.
Note that DATETIME, DATE, and TIME fields will always return the exact time you placed into them, regardless of the value of the time_zone variable.
TIMESTAMP fields will automatically convert their values to the timezone specified by the time_zone variable.
I need to change the timezone of a single database is this possible?
I know we can change the timezone within our WHM (we are using a dedicated server from hostgator), however a large number of legacy software running on the server has a lot of +6 hours coding in it (i.e. server timezone is CST, we wanted the time in GMT so previous developers altered date/times manually within the code - bad!).
I am now working on a new software and would like to have it all in GMT, I know I can use date_default_timezone_set('GMT') however that will not solve MySQL inserts where the datetime column is set to CURRENT_TIMESTAMP as it will insert # CST timezone.
No, it's not possible to change the timezone for a single database within a MySQL instance.
We can retrieve the server and client time_zone settings with a query, like this:
SELECT ##global.time_zone, ##session.time_zone;
We can also change the client timezone for a session, or change the timezone for the entire MySQL instance.
But we need to be keenly aware of the implication that this change will have on existing client connections, and the how DATETIME and TIMESTAMP values already stored in the instance will be interpreted.
To have the server time_zone set at MySQL instance startup, we can modify the /etc/my.cnf file (or wherever the mysql instance initialization parameters are read from), under the [mysqld] section:
[mysqld]
default-time-zone='+00:00'
-- or --
It is also possible (less desirable) to add the --default_time_zone='+00:00' option to mysqld_safe
NOTE: Changing the timezone setting on the MySQL server does NOT change the values stored in existing DATETIME or TIMESTAMP columns, BUT since it does effectively change the context in which those stored values are interpreted, it will look like all of the values ARE shifted. (Where 08:00 was taken to mean 8AM CST, with the time_zone of the server changed from CST to GMT, that same '08:00' will now be taken to be 8AM GMT, which would effectively be 2AM CST.
Also keep in mind that TIMESTAMP columns are always stored in UTC, while DATETIME columns do not have a timezone.
http://dev.mysql.com/doc/refman/5.5/en/datetime.html
Each client session can change the timezone setting for their own session:
SET time_zone='-06:00';
But none of this really "solves" the timezone conversion problem, it just moves the conversion problem around.
There's nothing inherently "bad" with the application layer handling timezone conversions; sometimes, that's the best place to handle. It just has to be done correctly and consistently.
(What's odd about the setup you describe is that the app is storing DATETIME values as if the MySQL server time_zone is set to GMT, but the MySQL server time_zone is set to something else.)
If you can't change your current time zone you can change the result.
date 2015-01-05 12:06:16
Select date + Interval 2 Hour 'date' From ExampleTable
date 2015-01-05 14:06:16
You can modify the the default value instead of entering current_timestamp make it insert current_timestamp added to hours offset of your timezone. I just did it this way when didn't found any solution, had to invent my own.
Currently whenever a user creates a new account, I have a Creation_date column that has datatype timestamp. Currently this timestamp reads 3 hours ahead of EST (if it's 5PM in Boston it reads 8PM). Is there a way to change the timezone to EST? What timezone is it set to currently?
This has to do with MySQL's timezone.
You can set it per connection (e.g. via PHPMyAdmin) with the following:
SET time_zone = timezone;
However, this will reset if MySQL restarts. So it is better set at the server level. Which, I assume, you can't.
I encourage you to read more from the MySQL Docs.
Accordingly with this question
SET SESSION time_zone = '+8:00'
TIMESTAMP values are converted to UTC when inserted into the DB and converted back to the current timezone set in MySQL on retrieval. The other answers show how to set the timezone in MySQL which will determine what value comes out of the database.
Another option is to use a DATETIME column, store ALL of your dates in UTC, and convert them to the desired timezone in your application (PHP or wherever you get the values from).
SET GLOBAL time_zone = timezone;
This is a COMPLETE example, for Argentina
SET GLOBAL time_zone = "-03:00";
you just need to change the "-03:00" for your timezone and run that command like a simple query, even in PhpMyAdmin.