Date.prototype.toISOString and Invalid Date

Garrett Smith dhtmlkitchen at
Thu Jun 11 01:24:59 PDT 2009

On Wed, Jun 10, 2009 at 8:56 PM, Adam Peller<apeller at> wrote:
> Douglas Crockford writes:
>>Adam Peller scripsit:
>>> I don't feel strongly on this, but it does strike me as odd that
>>> a function intended to avoid culturally-sensitive output would use
>>> an English phrase.  I'd lean towards IE/Opera, using notation from
>>> ECMAScript that is equally cryptic to all cultures :-)  At least that
>>> would be consistent with Number.toString() and would reinforce the fact
>>> that there are other methods to produce strings in the user's locale.
>>I think this is what exceptions are for.
>>An English string makes little sense.
>>NaN is nonsense.
> For toISOString I also favor an exception. The toString reference threw me
> off, since toString would not be able to throw in the invalid case and
> remain compatible. toString Implementations could certainly call
> toISOString, catch the exception, and choose some nonsensical, unspecified
> replacement,

Implementation of toString would probably not want to use try catch.
They might rather do something along the lines of:-

If the date is finite, return an implementation-dependent string
(which could be the resutl of toISOString). Otherwise, return an
implementation-dependent string (such as "invalid date").

A native method for generating a few of the popular or common ISO 8601
formats, such as the extended YYYY-MM-DD seems useful, to me. Is it
just me?

It seems that an "es5-discuss" list was created. I'm only subscribing
to es-discuss. It that a deprecated list? What is the difference
between these lists?


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