JS - Convert a "Europe/Berlin"-Date into a UTC-Timestamp - node.js

Inside my Docker-Container, which has the timezone Etc/UTC, I need to convert a Date-String which represents a Date in Europe/Berlin-timezone into a UTC timestamp.
So lets say the Europe/Berlin-Date is 2022-04-20T00:00:00.
Now the UTC-Timestamp should be equivalent to 2022-04-19T22:00:00.
But when I do
console.log(new Date("2022-04-20").getTime())
I get 1650412800000 which is equivalent to 2022-04-20T02:00:00 in Europe/Berlin-timezone.
How would I do this?
Edit:
I tried various libs, but still cant get that managed
const { DateTime } = require("luxon")
var f = DateTime.fromISO("2022-04-20").setZone('Europe/Berlin').toUTC()
console.log(f)
also the equivalent stamp in f is 2022-04-20T02:00:00 :/

I need to convert a Date-String which represents a Date in Europe/Berlin-timezone into a UTC timestamp.
Fundamentally, a date-only value cannot be converted into a timestamp, unless you arbitrarily associate a time with that date. It sounds like you meant to use midnight local time (00:00+02:00) but instead you are seeing midnight UTC (00:00Z).
This is due to how you are constructing the Date object. You specify new Date("2022-04-20"), which according to the ECMASCript spec will be treated as midnight UTC. The spec says:
... When the UTC offset representation is absent, date-only forms are interpreted as a UTC time and date-time forms are interpreted as a local time.
Yes, this is inconsistent with ISO 8601, and that has been discussed ad nauseum.
To solve this problem, append T00:00 to your input string, so that you are specifically asking for local time. In other words, new Date("2022-04-20T00:00").
That said, if you need it to not be "local time" but exactly Europe/Berlin, then yes - you'll need to use a library. In luxon, it's like this:
DateTime.fromISO('2022-04-20T00:00', {zone: 'Europe/Berlin'}).toUTC()

Related

why is output of date function on node.js server wrong?

When date was 2018-03-21 19:40, i tried following code
var date = new Date();
console.log(date);
Output :
2018-03-21T16:40:53.755Z
Server is missing for 3 hours as you see. I fixed it by adding 3 hours but I think it's not a good way. How can i fix this problem with better way ?
I don't think the date is incorrect, if you look closely at the format it is being printed, it has a Z at the end, which means:
A suffix which, when applied to a time, denotes a UTC offset of 00:00;
often spoken "Zulu" from the ICAO phonetic alphabet representation of
the letter "Z".
I guess you are in a place separated by 3 hours from UTC.
Node.js uses this format to print Date objects by default, but you can print your local time using toLocaleString():
console.log(date.toLocaleString());
Your server is most likely in another time zone.

How can I convert a variant VT_DATE to a string and include the time at midnight

I currently convert dates from variant format to string using the VariantChangeType (or CComVariant::ChangeType). That works well, except when the time portion of the variant value is midnight. In that case, the time is simply omitted from the converted string.
A timestamp of 2015/10/07 03:40:00 is converted to a string just as you would expect: "10/7/2015 03:40:00 AM" (using my regional settings).
But a timetamp of 2015/1007 00:00:00 is converted to this string: "10/7/2015" (no time portion included).
I'm trying to preserve that midnight time, and keep the regional settings in use too. I've looked at _strftime_l() - it does include a time in the converted string, but doesn't appear to use the regional settings, even when one is provided via _get_current_locale().
I'm using C++ on Windows.
Has anyone done this?
OK - I found a way to resolve this. Windows has two API calls that will format the date and time with regional settings: GetDateFormat() and GetTimeFormat(). They each take a SYSTEMTIME structure, an output buffer, and a locale specifier. On return, the output buffer contains the date (or time) converted to a string matching the locale and regional settings in use.
I also found that _strftime_l() will actually use regional settings if you call setlocal(LC_ALL, "") first. I was a bit leery of using that method as it may have side affects I'm not aware of.

Node's Postgres module pg returns wrong date

I have declared a date column in Postgres as date.
When I write the value with node's pg module, the Postgres Tool pgAdmin displays it correctly.
When I read the value back using pg, Instead of plain date, a date-time string comes with wrong day.
e.g.:
Date inserted: 1975-05-11
Date displayed by pgAdmin: 1975-05-11
Date returned by node's pg: 1975-05-10T23:00:00.000Z
Can I prevent node's pg to appy time-zone to date-only data? It is intended for day of birth and ihmo time-zone has no relevance here.
EDIT Issue response from Developer on github
The node-postgres team decided long ago to convert dates and datetimes
without timezones to local time when pulling them out. This is consistent
with some documentation we've dug up in the past. If you root around
through old issues here you'll find the discussions.
The good news is its trivially easy to over-ride this behavior and return
dates however you see fit.
There's documentation on how to do this here:
https://github.com/brianc/node-pg-types
There's probably even a module somewhere that will convert dates from
postgres into whatever timezone you want (utc I'm guessing). And if
there's not...that's a good opportunity to write one & share with everyone!
Original message
Looks like this is an issue in pg-module.
I'm a beginner in JS and node, so this is only my interpretation.
When dates (without time-part) are parsed, local time is assumed.
pg\node_modules\pg-types\lib\textParsers.js
if(!match) {
dateMatcher = /^(\d{1,})-(\d{2})-(\d{2})$/;
match = dateMatcher.test(isoDate);
if(!match) {
return null;
} else {
//it is a date in YYYY-MM-DD format
//add time portion to force js to parse as local time
return new Date(isoDate + ' 00:00:00');
But when the JS date object is converted back to a string getTimezoneOffset is applied.
pg\lib\utils.js s. function dateToString(date)
Another option is change the data type of the column:
You can do this by running the command:
ALTER TABLE table_name
ALTER COLUMN column_name_1 [SET DATA] TYPE new_data_type,
ALTER COLUMN column_name_2 [SET DATA] TYPE new_data_type,
...;
as descripted here.
I'd the same issue, I changed to text.
Just override node-postgres parser for the type date (1082) and return the value without parsing it:
import pg from pg
pg.types.setTypeParser(1082, value => value)

BigQuery / Node.js timestamp way off

Doing a streaming insert into Google BigQuery, from a light Node.js app, using this package: https://www.npmjs.org/package/bigquery
I generated a timestamp on my server via this simple line of code:
jsonData['createdAt'] = new Date().getTime();
I then insert that into BigQuery, into a field with type 'timestamp'. There is no intermediate step (besides the Node package).
But many, although not all, of dates look waaaaaay off. For example:
46343-08-28 05:58:59 UTC
When that should say something like 11:45pm on 05-16-2014. However, some of my createdAt dates are correct, and I can't find a reason for the difference.
Any suggestions?
Without actually debugging the JS code, this seems to be an "off by a thousand" problem.
Check this out:
SELECT USEC_TO_TIMESTAMP(1400341611711851)
2014-05-17 15:46:51 UTC
SELECT USEC_TO_TIMESTAMP(1400341611711851*1000)
46345-01-22 13:01:51 UTC
SELECT MSEC_TO_TIMESTAMP(1400341611711851)
46345-01-22 13:01:51 UTC
SELECT MSEC_TO_TIMESTAMP(1400341611711851/1000)
2014-05-17 15:46:51 UTC
So to get a UNIX timestamp in seconds, divide the new Date().getTime() number by 1000.
I had a requirement where I am supposed to send Timestamp type to BigQuery table from NodeJS.
I did it as follows:
bigqueryClient.timestamp(new Date(Date.now()))
I hope this may help someone.
Use:
bigquery.datetime(new Date().toISOString())

Timezone format connections

I got the time values from the SBT SDK as a string in this format
"2013-07-17T14:44:25.177Z"
I get a Java Date object with this code
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
Date date = dateFormat.parse("2013-07-17T14:44:25.177Z");
But the last part of the string ".177Z" should be a time zone value !?!?!
Do any body know how parse the time zone or the complete date with the time zone in Java?
Thx
Andreas
But the last part of the string ".177Z" should be a time zone value !?!?!
No, I think the .177 is the milliseconds part, and Z is a UTC-offset of 0. (It's not really a time zone, but that's a different matter.)
I suspect you want:
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSX");
(Where X is an ISO-8601 time zone specifier, including Z for UTC.)
Note that X was only introduced in Java 7 - if you're using Java 6 or earlier, you may need to do a bit more work.
You might want to use
javax.xml.bind.DatatypeConverter.parseTime(String)
since the dates found in the atom returned by the IBM Connections API conform to the definition from http://www.w3.org/TR/xmlschema-2/, which can be parsed into a Java Calendar Object by said method. This also accounts for the time zone specifier.

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