CODEWITHSUNDEEP
javamongodbjava.util.date
Harshana
Harshana

Reputation: 7647

Save TimeZone with Date in mongodb

I have java.util.Date field in my document class.

E:g:

@Document(collection = "testdoc")
public class TestDoc {
    @Id
    String id;
    Date startDate;
}

Even if I set the Date with UTC and IST, it always save in my collection as below,

 "startDate" : ISODate("2015-08-21T18:30:00.000Z")

How can I save the time zone also in mongo collection? What does Z stand in this case?

Upvotes: 6

Views: 43395

Answers (4)

FishingIsLife
FishingIsLife

Reputation: 2372

I guess here you'll find a good guideline how to handle timestamps in different scenarios for different data language independent. As it's recommendet in the document, ALWAYS use UTC to save the data, even it is local timezone. If necessary, save the time zone in a seperate field ( JSON or xml) and follw the format guideline ISO 8601. ( like you did but there are many possible representations) As far as I know, correct me if i'm wrong, JSOn does not deal with specific date formats but JS does. Microsoft docs recommends the followind format bases on ECMA YYYY-MM-DDTHH:mm:ss.sssZ this The Z in the Timestamp shows that it's UTC format with zero offset +00:00 if nothing else is added. If you want to use the "Z" notation, you have to add or substract the offset within the timestamp instead of writing the zero-offset and add the offset at the end. I recommend you to follw the w3c guideline because it covers different scenatios for different time saving usecases. Hope this helps

Upvotes: 1

CodeMonkey
CodeMonkey

Reputation: 12424

Dates in MongoDB are stored in UTC. There isn't timestamp with a timezone data type like in some relational databases. Applications that need to access and modify timestamps, based on local time, should store the timezone offset together with the date and offset dates on an application level.

In the MongoDB shell, this could be done using the following format with JavaScript:

let now = new Date();
db.page_views.save({date: now,                    
                    offset: now.getTimezoneOffset()});

Then you need to apply the saved offset to reconstruct the original local time, as in the following example:

let record = db.page_views.findOne();
let localNow = new Date( record.date.getTime() - ( record.offset * 60000 ) );

Upvotes: 2

Anirudh Srinivas Madhavan
Anirudh Srinivas Madhavan

Reputation: 131

The 'Z' signifies that the time is stored in UTC. Mongo internally converts all local representations of time in UTC before storing. However, one suggestion would be to store the time along with the timezone which is received from your application. You can later reconstruct the local time from the UTC time and the timezone in your application logic.

Please go through this link. They have given an example on how to model local time data using JavaScript.

https://docs.mongodb.com/v3.2/tutorial/model-time-data/

Upvotes: 11

mhasan
mhasan

Reputation: 3709

Do the conversion before storing and save as UTC always. Then reconvert it in the timezone you want before displaying.

If you desperately want to store the timezone with the offset you may have to deal with it as a separate string in db, but it cannot go with date field for MongoDB.

As currently MongoDB doesn't allow saving of timezone. Below is the open JIRA issue or the same.

https://jira.mongodb.org/browse/SERVER-6310

Upvotes: 10

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