What is the “right” JSON date format?

Question

I\'ve seen so many different standards for the JSON date format:

\"\\\"\\\\/Date(1335205592410)\\\\/\\\"\"         .NET JavaScriptSerializer
\"\\\"\\\\/Date(         


        

Answer 1

I think that really depends on the use case. In many cases it might be more beneficial to use a proper object model (instead of rendering the date to a string), like so:

{
"person" :
      {
 "name" : {
   "first": "Tom",
   "middle": "M",
  ...
}
 "dob" :  {
         "year": 2012,
         "month": 4,
         "day": 23,
         "hour": 18,
         "minute": 25,
         "second": 43,
         "timeZone": "America/New_York"
    }   
   }
}

Admittedly this is more verbose than RFC 3339 but:

• it's human readable as well
• it implements a proper object model (as in OOP, as far as JSON permits it)
• it supports time zones (not just the UTC offset at the given date and time)
• it can support smaller units like milliseconds, nanoseconds, ... or simply fractional seconds
• it doesn't require a separate parsing step (to parse the date-time string), the JSON parser will do everything for you
• easy creation with any date-time framework or implementation in any language
• can easily be extended to support other calendar scales (Hebrew, Chinese, Islamic ...) and eras (AD, BC, ...)
• it's year 10000 safe ;-) (RFC 3339 isn't)
• supports all-day dates and floating times (Javascript's Date.toJSON() doesn't)

I don't think that correct sorting (as noted by funroll for RFC 3339) is a feature that's really needed when serializing a date to JSON. Also that's only true for date-times having the same time zone offset.