Is Date.Today in Utc

How to convert datetime.date.today() to UTC time?

Use utcnow:

today = datetime.datetime.utcnow().date()

Is Date.today in UTC?

TL;DR: Date.today uses the system’s local time zone. If you require it be in UTC, instead get the date from a UTC time, e.g. Time.now.utc.to_date.

Dates do not have timezones, since they don't represent a time.

That said, as for how it calculates the current day, let's look at this extract from the code for Date.today:

time_t t;
struct tm tm;
// ...
if (time(&t) == -1)
  rb_sys_fail("time");
if (!localtime_r(&t, &tm))
  rb_sys_fail("localtime");

It then proceeds to use use tm to create the Date object. Since tm contains the system's local time using localtime(), Date.today therefore uses the system's local time, not UTC.

You can always use Time#utc on any Time convert it in-place to UTC, or Time#getutc to return a new equivalent Time object in UTC. You could then call Time#to_date on that to get a Date. So: some_time.getutc.to_date.

If you’re using ActiveSupport’s time zone support (included with Rails), note that it is completely separate from Ruby’s time constructors and does not affect them (i.e. it does not change how Time.now or Date.today work). See also ActiveSupport extensions to Time.

How can I get the current date and time in UTC or GMT in Java?

java.util.Date has no specific time zone, although its value is most commonly thought of in relation to UTC. What makes you think it's in local time?

To be precise: the value within a java.util.Date is the number of milliseconds since the Unix epoch, which occurred at midnight January 1st 1970, UTC. The same epoch could also be described in other time zones, but the traditional description is in terms of UTC. As it's a number of milliseconds since a fixed epoch, the value within java.util.Date is the same around the world at any particular instant, regardless of local time zone.

I suspect the problem is that you're displaying it via an instance of Calendar which uses the local timezone, or possibly using Date.toString() which also uses the local timezone, or a SimpleDateFormat instance, which, by default, also uses local timezone.

If this isn't the problem, please post some sample code.

I would, however, recommend that you use Joda-Time anyway, which offers a much clearer API.

How to convert a Date to UTC?

The toISOString() method returns a string in simplified extended ISO
format (ISO 8601), which is always 24 or 27 characters long
(YYYY-MM-DDTHH:mm:ss.sssZ or ±YYYYYY-MM-DDTHH:mm:ss.sssZ,
respectively). The timezone is always zero UTC offset, as denoted by
the suffix "Z".

Source: MDN web docs

The format you need is created with the .toISOString() method. For older browsers (ie8 and under), which don't natively support this method, the shim can be found here:

This will give you the ability to do what you need:

var isoDateString = new Date().toISOString();
console.log(isoDateString);

import pytz
from datetime import datetime
datetime.utcnow().replace(tzinfo=pytz.utc)

datetime.now(pytz.utc)

import {formatDate} from '@angular/common';
today = formatDate(new Date(), 'yyyy-MM-dd hh:mm:ss', 'en', '+0000'); 

console.log(formatDate(new Date(), 'yyyy-MM-ddThh:mm:ssZZZZZ', 'en', 'GMT'))

let datenow = new Date();

console.log(datenow); // "2021-07-28T18:11:11.282Z"
console.log(generateDatabaseDateTime(datenow)); // "2021-07-28 14:11:33"

function generateDatabaseDateTime(date) {
  return date.toISOString().replace("T"," ").substring(0, 19);
}