Date.date

[retorquere]

I'm trying to get the day-of-month value from a parsed date, but I'm getting some things I didn't expect:

edtf('2016-07-18T20:26:06+10:00').date = 19
edtf('-0876').date = 1

I sort of get the first, but I'd still prefer to have a way to get 18 out. The 2nd, I had expected undefined rather than 1.

[inukshuk]

Regarding the first example: we are always converting to UTC, because otherwise a number of important calculations would become insanely difficult or simply impossible. The date is still correct, so you can calculate it according to your desired timezone. If you are just interested in the string representation (i.e., get 18 out) then don't use the date library, just parse the string:

e.parse('2016-07-18T20:26:06+10:00').values[2]
// -> 18

Similarly for the second example, don't use the date library if you just want to parse the numbers:

e.parse('-0876').values[2]
// -> undefined

The point of the date library is to manipulate dates and convert them back to EDTF strings. For that reason, we're using the concept that every extended date covers a period of time with a min/max value. This approach is necessary to do computations, that's why the day exists, even though the date has year precision (you can still query the precision and convert the date back to a string and you will see that there is no day set, but because it is required for computations you can still get an approximation if you need it).

[retorquere]

Please do let me know if this is not the proper channel... if I parse 1999-XX-XX I get (as expected) { values: [ 1999, 0, 1 ], unspecified: 240, type: 'Date', level: 1 }, but .unspecified.is(...) clearly won't work here. How do I call Bitmask directly to find out what part is unspecified?

[retorquere]

Or could I just use edtf('...').values and edtf('...').unspecified.is(...)?

[inukshuk]

Yes, you can either use the extended date objects directly, or, alternatively, use the Bitmask class (unspecified and uncertain are simply Bitmask instances created from the numeric value returned by the parser).