Subject: Re: [PATCH v3] date: make "iso-strict" conforming for the UTC timezone

From: Junio C Hamano <[email-masked]>
Date: Wed, 13 Mar 2024 16:06:33 -0700

"Beat Bolli" <[email-masked]> writes:

> ISO 8601-1:2020-12 specifies that a zero timezone offset must be denoted
> with a "Z" suffix instead of the numeric "+00:00". Add the correponding
> special case to show_date() and a new test.
>
> Changing an established output format which might be depended on by
> scripts is always problematic, but here we choose to adhere more closely
> to the published standard.

Perfect.  Thanks for following it through.  Will replace (I've
queued v2 already but it is easy to replace).

>
> Reported-by: Michael Osipov <[email-masked]>
> Signed-off-by: Beat Bolli <[email-masked]>
> ---
> Changes from v2:
>
> - changed the rationale according to Junio's feedback
>
> Changes from v1:
>
> - added a comment why the change is fine
> - removed the Link: trailer
>
>  date.c          | 14 +++++++++-----
>  t/t0006-date.sh |  1 +
>  2 files changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/date.c b/date.c
> index 619ada5b2044..44cf2221d81f 100644
> --- a/date.c
> +++ b/date.c
> @@ -342,14 +342,18 @@ const char *show_date(timestamp_t time, int tz, const struct date_mode *mode)
>  				tm->tm_hour, tm->tm_min, tm->tm_sec,
>  				tz);
>  	else if (mode->type == DATE_ISO8601_STRICT) {
> -		char sign = (tz >= 0) ? '+' : '-';
> -		tz = abs(tz);
> -		strbuf_addf(&timebuf, "%04d-%02d-%02dT%02d:%02d:%02d%c%02d:%02d",
> +		strbuf_addf(&timebuf, "%04d-%02d-%02dT%02d:%02d:%02d",
>  				tm->tm_year + 1900,
>  				tm->tm_mon + 1,
>  				tm->tm_mday,
> -				tm->tm_hour, tm->tm_min, tm->tm_sec,
> -				sign, tz / 100, tz % 100);
> +				tm->tm_hour, tm->tm_min, tm->tm_sec);
> +		if (tz == 0) {
> +			strbuf_addch(&timebuf, 'Z');
> +		} else {
> +			strbuf_addch(&timebuf, tz >= 0 ? '+' : '-');
> +			tz = abs(tz);
> +			strbuf_addf(&timebuf, "%02d:%02d", tz / 100, tz % 100);
> +		}
>  	} else if (mode->type == DATE_RFC2822)
>  		strbuf_addf(&timebuf, "%.3s, %d %.3s %d %02d:%02d:%02d %+05d",
>  			weekday_names[tm->tm_wday], tm->tm_mday,
> diff --git a/t/t0006-date.sh b/t/t0006-date.sh
> index e18b1602864e..1d228a981ee9 100755
> --- a/t/t0006-date.sh
> +++ b/t/t0006-date.sh
> @@ -46,6 +46,7 @@ check_show () {
>  TIME='1466000000 +0200'
>  check_show iso8601 "$TIME" '2016-06-15 16:13:20 +0200'
>  check_show iso8601-strict "$TIME" '2016-06-15T16:13:20+02:00'
> +check_show iso8601-strict "$(echo "$TIME" | sed 's/+0200$/+0000/')" '2016-06-15T14:13:20Z'
>  check_show rfc2822 "$TIME" 'Wed, 15 Jun 2016 16:13:20 +0200'
>  check_show short "$TIME" '2016-06-15'
>  check_show default "$TIME" 'Wed Jun 15 16:13:20 2016 +0200'