MySQL query for current GMT time

问题

This sounds simple enough but I haven't been able to figure out how to use a simple SELECT statement to return the current time in GMT.

I have been trying to use CONVERT_TZ() to convert NOW() to GMT based on the server time zone and the GMT time zone but for some reason it returns NULL when I put in the text time zones. The only way I get a result is to actually put in the offsets which is getting way too complicated for what should be a really simple operation. Here is what I mean:

mysql> SELECT CONVERT_TZ(NOW(),@@global.system_time_zone,'GMT');
NULL

mysql> SELECT CONVERT_TZ(NOW(),'PST','GMT');
NULL

mysql> SELECT CONVERT_TZ(NOW(),'-08:00','+00:00');
2010-02-13 18:28:22

All I need is a simple query to return the current time in GMT. Thanks in advance for your help!

回答1:

Just use UTC (doesnt get affected with daylight savings time)

SELECT UTC_TIMESTAMP();

---

Old Content for reference:

this should work, but with

SELECT CONVERT_TZ(NOW(),'PST','GMT');

i got also NULL as result. funny enough the example in the mysql docu also returns null

SELECT CONVERT_TZ('2004-01-01 12:00:00','GMT','MET');

http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html#function_convert-tz seems you found a bug in mysql. (thanks to +Stephen Pritchard)

you could try:

SET @OLD_TIME_ZONE=@@TIME_ZONE;
SET TIME_ZONE='+00:00';
SELECT NOW();
SET TIME_ZONE=@OLD_TIME_ZONE;

ok is not exactly what you wanted (its 4 queries, but only one select :-)

回答2:

NO BUG in CONVERT_TZ()

To use CONVERT_TZ() you need to install the time-zone tables otherwise MySql returns NULL.

From the CLI run the following as root

# mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root mysql

SEE http://dev.mysql.com/doc/refman/5.5/en/time-zone-support.html

Thanks

http://www.ArcanaVision.com (SJP 2011-08-18)

回答3:

Note: GMT might have DST UTC does not have DST

SELECT UTC_TIMESTAMP();

I made a cheatsheet here: Should MySQL have its timezone set to UTC?

回答4:

The surefire way to fetch the current UTC datetime is:

SELECT CONVERT_TZ(NOW(), @@session.time_zone, '+0:00')

回答5:

After seeing all the answers above and seeing it's unreliable to convert to PST, I just used this:

DATE_SUB(user_last_login, INTERVAL 7 hour)

回答6:

This should work - I think you are specified your timezone wrong. Using Chicago as example

SELECT CONVERT_TZ(NOW(), 'America/Chicago', 'GMT')

回答7:

When the source server timestamp is unknown but the requirement is for a specific tz do this:

select convert_tz(utc_timestamp(),'+05:00','+00:00')

This uses CST as an example. utc_timestamp will guarantee a '+00:00' result no matter where you query it. The '+05:00' is your desired offset. This works great when hitting multiple unknown servers and it assures you that you returning result will all be in a common tz result set.

回答8:

I was searching for my time zone which is GMT+6 (Asia/Dhaka TimeZone)

MySQL server is in US. The below worked for me.

SELECT CONVERT_TZ( UTC_TIMESTAMP( ) , '+06:00', '+00:00' )

回答9:

There is no bug in CONVERT_TZ function. You get NULL because you use time zones names/abbreviations. Mysql does not know what this 'GMT','PST', etc means unless you install mysql.time_zone_name table. However if you use numbers it will always work.

mysql> SELECT CONVERT_TZ(NOW(), 'America/Chicago', 'GMT');

returns NULL

mysql> SELECT CONVERT_TZ(NOW(),'-08:00','+00:00');

returns 2016-06-24 17:58:33

来源：https://stackoverflow.com/questions/2258274/mysql-query-for-current-gmt-time