datetime UTC conversion in mongodb

Question

I do new Date() then save it into mongodb, the date became UTC format?

The datetime I inserted into mongodb when pull back is not the same, what should I do to solve this? Like I create a document on 1/12/2016, and I select range from 1/12/2016, the record is not there. Strange.

score 0 · Answer 1 · edited May 23 '17 at 12:08

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The default timezone for node.js new Date() object is UTC (aka GMT).

You should leave it this way and just convert it on your front end. Javascript in the browser can convert the UTC timestamp to the browsers local timezone automatically.

new Date(Date.UTC(saved-timezone))

How do you create a JavaScript Date object with a set timezone without using a string representation

edited May 23 '17 at 12:08

Community

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answered Dec 01 '16 at 07:50

Porlune

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so basically I can't do new Date() but Date.UTC(saved-timezone) if I want to use mongodb? – Jessie Emerson Dec 01 '16 at 07:51
You always want to save dates in UTC and then convert them to the local timezone after they are retrieved. Just leave it as UTC, and use the code above to translate the time into the local timezone after retrieval. – Porlune Dec 01 '16 at 07:54
convert time in front end after retrieved? – Jessie Emerson Dec 01 '16 at 07:55
If you want the local timezone of the browser to be displayed then yes. – Porlune Dec 01 '16 at 08:25

score 0 · Accepted Answer · edited May 23 '17 at 12:24

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As the documentation says :

The mongo shell wraps the Date object with the ISODate helper. The ISODate is in UTC.

So my best guess is that your new Date() is not in UTC.

Math.floor((new Date()).getTime() / 1000)

as seen here: How do I get a UTC Timestamp in JavaScript?

However, Mongo is smart enough to sort this all out for you, so new Date() should be enough.

To query a Date in mongo, you can also use pure Date Objects, without the need to convert them to ISOString.

Keep everything as Date Objects, and it'll work as you intend it to!

edited May 23 '17 at 12:24

Community

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answered Dec 01 '16 at 07:51

xShirase

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so basically I can't do new Date() but Date.UTC(saved-timezone) if I want to use mongodb? – Jessie Emerson Dec 01 '16 at 07:52
You shouldn't need that though, Mongo is clever enough to sort it all out for you. could you show us what you insert, and what is written in the mongo doc? – xShirase Dec 01 '16 at 07:54
if that is the case why should I have that strange error? – Jessie Emerson Dec 01 '16 at 07:55
maybe your query? – xShirase Dec 01 '16 at 07:55
Are you sure? Can you help to take a look? http://pastebin.com/g7YEd7a5 – Jessie Emerson Dec 01 '16 at 07:56
yes, you're converting your dates with toIsoString(), you don't need to do that – xShirase Dec 01 '16 at 07:57
so just return d? removing the firstDayOfMonth will solve my problem? are u sure? – Jessie Emerson Dec 01 '16 at 08:02
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/129504/discussion-between-xshirase-and-jessie-emerson). – xShirase Dec 01 '16 at 08:02
my 2 function return this {"firstDayOfMonth":"2016-11-01T09:45:30.998Z","lastDayOfMonth":"2016-11-30T09:45:30.998Z"}. why is the range is so strange? – Jessie Emerson Dec 01 '16 at 09:46

datetime UTC conversion in mongodb

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