Any suggestions for how to handle Dates in JSON?

[andrewducker]

Because JSON doesn't support a standard date format I'm going to have to serialise/deserialise to _something_. A quick google has found me numerous different approaches - anyone care to point me at a specific best practice

Comments

[andrewducker]

http://www.hanselman.com/blog/OnTheNightmareThatIsJSONDatesPlusJSONNETAndASPNETWebAPI.aspx seems to indicate that I should be using ISO 8601. Which seems like a plausible route to take.

[ciphergoth]

There are *lots* of ways of writing dates in ISO 8601. I'd use specifically UTC RFC 3339 dates: 1985-04-12T23:20:50.52Z

[skington]

I don't know what libraries / languages you're using, or what's easiest, but thankfully as you're talking about JSON that doesn't matter. JSON is a serialisation format, so all that matters is that your data is obvious, unsurprising and easy.

So I'd say a choice between SQL DATETIME format (yyyy-mm-dd hh:mm:ss) and, as mentioned elsewhere, ISO 8601. I mildly prefer DATETIME because it's more legible than ISO 8601, but meh.

Above all, (1) don't use stupid US-style date formats, and (2) store all dates, ever, in UTC. Do not fuck about with time zones.

[momentsmusicaux]

> Above all, (1) don't use stupid US-style date formats, and (2) store all dates, ever, in UTC. Do not fuck about with time zones.

Yes to both, absolutely.

If you need to output in a specific timezone, store that fact as a separate piece of data, and convert on output.

[channelpenguin]

YES YES YES to these 2

[apostle_of_eris]

+1

[mark_nicol]

Another +1 - No-one ever got cursed for keeping things simple and legible

[momentsmusicaux]

Unix timestamp? Or do you need partial dates?

Otherwise, the ISO format, which does. (2014-02-01T08:04:00)

If your language has serialization of its own, then you could use that and just give JSON the string (as you could in PHP, if you had DateTime objects).

[andrewducker]

Yeah, I think Unix Timestamp is the way to go.

My two languages are Java (which can easily convert to/from Epoch) and Javascript (ditto).

[momentsmusicaux]

The downside with unix timestamp is that it's a PITA for humans to read.

I have lost count of the number of times I've had to type FROM_UNIX() or whatever the SQL function is to make my database queries produce something I can actually understand when debugging.

[andrewducker]

True.

But on the other hand, I'm converting it into a JS Date at the point where it's being read into the UI. So I'm never actually having to deal with a timestamp by eye - I'm either seeing it in the Java debugger as a DateTime object, or in the JS debugger as a Date object.

If I was writing it for something other people would use from different front ends then yeah, readability would definitely be a factor.