Objective:
Knowing that my main column dates is in UTC time but is taking data from the Time zone 'Dateline Standard Time', how can I ensure that my query accounts for the offset without having to manually do DATEADD(HOUR,-8,column_name). This is especially important for day light savings periods.
select
, created_at
, created_at at time zone 'Dateline Standard Time' as dates_zone
The output of this is:
created_at created_at_timezone
2019-07-01 00:45:04.000 2019-07-01 00:45:04.000 -12:00
but I'd rather have the end result as such:
(which is basically UTC-8)
created_at_modified
2019-06-30 16:45:04.000
You can convert the date to datetimeoffset:
SELECT CONVERT(datetimeoffset,created_at) AT TIME ZONE 'Dateline Standard Time' created_at_modified
FROM …
;
Related
I have 2 separate fields for date and time. The time field is stored in UTC time. How can I combine the 2 into a datetime field into local time
Example:
date: 2021-03-08
time in UTC: 23:00
time zone: GMT+8
I would like to get 2021-03-08 07:00 in local time
or even 2021-03-07 23:00 in UTC
Note: Combining the fields is not an option unfortunately.
Need to know your time zone to convert. To convert utc to america/los_angeles time zone:
select '2021-03-08 23:00'::timestamp at time zone 'UTC' at time zone 'america/los_angeles'
you can check out below codes:
If you have a timestamp without time zone column and you're storing timestamps as UTC, you need to tell PostgreSQL that, and then tell it to convert it to your local time zone.
select created_at at time zone 'utc' at time zone 'america/los_angeles'
from users;
To be more concise, you can also use the abbreviation for the time zone:
select created_at at time zone 'utc' at time zone 'pst'
from users;
To see the list of time zones PostgreSQL supports:
select * from pg_timezone_names;
SInce the time difference is 8 hours, try
SELECT '2021-03-08'::date + ('23:00'::time + '8 hours'::interval);
If you want this to work with arbitrary time zones, the query becomes more complicated:
SELECT '2021-03-08'::date
+ ((current_date + '23:00'::time)
AT TIME ZONE 'UTC'
AT TIME ZONE 'Asia/Ulaanbaatar'
)::time;
I have a PostgreSQL table named testing with a column named creation_time as timestamp with time zone. The database timezone is UTC
Now I want to get all rows whose time is greater than 00:00 of the current day as per the timezone "America/New_York".
I know how to get all rows after local midnight:
SELECT * FROM testing
WHERE ( creation_time >= now()::date)
ORDER BY id DESC
But how to use this query with a different timezone?
Assuming "the current day" is also defined by NY time, not by the current timezone setting.
SELECT *
FROM testing
WHERE creation_time >= date_trunc('day', now() AT TIME ZONE 'America/New_York') AT TIME ZONE 'America/New_York'
ORDER BY id DESC;
Yes, AT TIME ZONE 'America/New_York' twice. No typo there.
now() AT TIME ZONE 'America/New_York') gets local NY time. date_trunc gets 00:00 of that day. The 2nd AT TIME ZONE 'America/New_York' converts the local time back to timestamptz, which we finally compare to.
If you want NY 00:00 of your local date, it's simpler:
WHERE creation_time >= CURRENT_DATE::timestamp AT TIME ZONE 'America/New_York'
Same time, but can be a different day!
CURRENT_DATE is the local date (date according to the time zone setting of the current session). Effectively the same as now()::date.
Further reading:
Ignoring time zones altogether in Rails and PostgreSQL
I am working with time data that is currently stores in UTC but I want it to be in PST, which is 8 hours behind. I have a pretty lengthy and involved query, but the only thing I am interested in is the time right now so I have included those parts. I want to convert the times to PST and then group by the date for the last week of data. The query has the following structure:
select
date_trunc('day', time1) AT TIME ZONE 'US/Pacific'
...
where
time1 AT TIME ZONE 'US/Pacific' > now() AT TIME ZONE current_setting('TimeZone') - INTERVAL '168 HOURS'
...
group by date_trunc('day', time1)
This results in the following time groupings. From my understanding, it groups from the 0:00 UTC, which is 16:00 in PST. However, I want the groupby to start at 0:00 PST. How do I do this? Right now, the counts in each group are misleading for each day because they go from 4 pm to 4 pm instead of 12 am to 12 am. For example, Sundays have uncharacteristically high counts because Sunday includes part of Monday's data in the groupby. I would appreciate any input to fix this issue. Thank you.
The answer depends on whether it is a timestamp with time zone or one without:
If it's a timestamp with time zone, you can convert to PST with select time1 AT TIME ZONE 'US/Pacific' and get the date with select date_trunc('day', time1 AT TIME ZONE 'US/Pacific')
If it's a timestamp without time zone stored in UTC that you want to convert, you first have to tell PostgreSQL to interpret it as UTC, then convert it, like so: select (time1 AT TIME ZONE 'Z') AT TIME ZONE 'US/Pacific' and of course you can get the date with select date_trunc('day', (time1 AT TIME ZONE 'Z') AT TIME ZONE 'US/Pacific')
In either case you have to convert time zones before truncating to the day level or you may end up with inaccurate results.
I am storing datetime field with UTC time. We have a requirement to filter the records with CST timezone.
I have tried this query:
select id, CreatedOn,
CreatedOn AT TIME ZONE 'UTC' AT TIME ZONE 'Central Standard Time' AS LocalTime
from Status
WHERE CAST((CreatedOn AT TIME ZONE 'Central Standard Time') AS date) = '2018-09-06'
order by CreatedOn desc;
The issue is that it is also bringing those records which were saved on September 5th CST time in the evening when the UTC time was changed to 6th September. What is the correct way to filter out only September 6th records in CST time?
I found an issue with the query, I was missing 'UTC' AT TIME ZONE in the where clause. Here is the correct query which works:
select id, CreatedOn,
CreatedOn AT TIME ZONE 'UTC' AT TIME ZONE 'Central Standard Time' AS LocalTime from CosmoStatus WHERE CAST((CreatedOn AT TIME ZONE
'UTC' AT TIME ZONE 'Central Standard Time') AS date) = '2018-09-06'
order by CreatedOn desc;
I have a date and time variable in TABLE_A that is in GMT. I want to insert this date and time into TABLE_B, but I want the insterted value to be adjusted for time zone and summer/winter time.
That is:
INSERT into TABLE_A (ADJUSTED_DATE_AND_TIME)
SELECT GMT_DATE_AND_TIME [Perform proper adjustments here..?]
FROM TABLE_A
Can I do this? In that case, how do I write ?
Thank.
I think you can simply convert the GMT/UTC time. However, you have to take the full region name of your time zone.
SELECT TIMESTAMP '2014-06-10 12:00:00 +00:00' AT TIME ZONE 'Europe/Zurich' AS summer FROM dual;
SUMMER
---------------------------------------
10.06.2014 14:00:00.000000000 +02:00
SELECT TIMESTAMP '2014-12-10 12:00:00 +00:00' AT TIME ZONE 'Europe/Zurich' AS winter FROM dual;
WINTER
---------------------------------------
10.12.2014 13:00:00.000000000 +01:00
Since your source value is data type DATE you have to do following steps.
Cast DATE to TIMESTAMP
Set Time zone of the value using FROM_TZ
Convert the value to new time zone using AT TIME ZONE '...'
Cast the value to DATE
Written in a single statement it is
select
CAST(FROM_TZ(CAST(sy_sttime AS TIMESTAMP), 'UTC') AT TIME ZONE 'Europe/Zurich' AS DATE)
from sy_request
or a bit less clear
select
CAST((CAST(sy_sttime AS TIMESTAMP) AT TIME ZONE 'UTC') AT TIME ZONE 'Europe/Zurich' AS DATE)
from sy_request