Where should dates be formatted?

[NotionCommotion]

When just generating HTML, where should dates be formatted?  What about when generating JSON (I've found that date formatting is not so straight forward using JavaScript)?  Are there factors which may make one approach better than the other (i.e. querying one record versus a list of records)?  How important is consistency of an approach?  Any other factors I should consider?  Please provide rational for your decision.  Thank you

 

 

At the database?

DATE_FORMAT(my_date, "%m/%d/%Y %r") AS my_date

In the controller?

$date = new DateTime($my_date);
$my_date=$date->format('m/d/Y');

In a twig or smarty template?

{{ mydate|date("m/d/Y g:i A") }}

At the client using handlebars and the Moment library?

UI.registerHelper("formatDate", function(datetime, format) {
if (moment) {
f = DateFormats[format];
return moment(datetime).format(f);
}
else {
return datetime;
}
});

...

{{formatDate MyISOString "short"}}

[Jacques1]

Formatting is a presentational task, so it should be done in the template when the output is generated.

 

It's a bad idea to format the date at database level or in the controller:

• What if you need to actually do something with the date in the application? Then the custom format will be in the way.
• What if you decide to support multiple formats? Do you put a big CASE block into every single query? Do you write a custom SQL function only to format dates? Both will be a pain in the ass. You might also have to pass a format parameter to the database system so that it knows which format to choose.

[NotionCommotion]

Thanks Jacques,

 

What if the server is generating JSON instead of HTML?

[Jacques1]

What is the JSON document used for? In general, JSON documents carry raw data, so you'd use the raw, unformatted date.

[NotionCommotion]

What is the JSON document used for? In general, JSON documents carry raw data, so you'd use the raw, unformatted date.

 

The JSON document is a list of data which is used to add content to the current page where the dates should be formatted like "10/09/2014 09:31:41 AM".  Yes, it "could" be parsed client side, however, JavaScript doesn't seem to have a clean way of doing so.

[
    {"id":123,"filename":"someFile1.pptx","datetime":"2014-10-09 09:31:41","size":"6299 KB"},
    {"id":321,"filename":"someFile2.pptx","datetime":"2014-10-29 04:35:42","size":"4629 KB"},
    {"id":444,"filename":"someFile3.pptx","datetime":"2014-10-19 02:33:43","size":"6599 KB"}
]