[tz] localized date without time

[Alejandro Colomar]

Hi Paul,

Link: <https://github.com/shadow-maint/shadow/issues/1057>

Currently, shadow utils' passwd(1) (and several other programs) uses UTC
time when printing.

That is:

	$ passwd -S alx
	alx P 2023-09-20 0 99999 7 -1

the date from above is a UTC representation of

	$ sudo cat /etc/shadow | grep alx | cut -f3 -d:
	19620

However, shadow utils programs, such as chage(1), use local time in
input.  That timestamp was set by chage(1), interpreting a local date:

	$ sudo chage -d 2023-09-21 alx
	$ sudo cat /etc/shadow | grep alx | cut -f3 -d:
	19620
	$ date
	Wed Jul 31 07:54:17 CEST 2024

This is rather confusing, and we think that passwd(1) should also print
the date in local time, when printing human-readable dates.  However, I
think it might be better to show the timezone information together with
the date, to be clear that what we're printing is local time.  Do you
think that's reasonable?  Or maybe it's understood that when printing a
date some timezone information is implicitly local?

I didn't find any way to print timezone information in ISO 8601, if you
don't print the time together with the date.  That is, ISO 8601 says:

	C.1.3.1 Date

	A date string represents one of the following:

	• year, month, and day (e.g. 2001-02-03)
	• year and month (e.g. 2008-12 )
	• year (e.g. 2008)

and

	C.1.3.2 Date and Time

	A date/time string is composed according to one of three
	representations as illustrated in the following three examples:

	• 2001-02-03T09:30:01
	• 2004-01-01T10:10:10Z
	• 2004-01-01T10:10:10+05:00

but I don't see any way to print something like 2023-09-21+02:00 in
standardese.  Is this a defect in ISO 8691?

I see that in C.1.3.2, it says "Zone-offset may be omitted or included",
so I guess we can just omit it.

What do you think we should do?


Thanks!
And have a lovely day!
Alex 


-- 
<https://www.alejandro-colomar.es/>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <https://mm.icann.org/pipermail/tz/attachments/20240731/2a920377/signature.asc>