[m-rev.] for review: allow for only a single positive leap second

[Zoltan Somogyi]

On Tue, 14 Apr 2026 21:58:28 +1000, Julien Fischer <jfischer at opturion.com> wrote:
> diff --git a/NEWS.md b/NEWS.md
> index d70465ef1..3e78b3c8c 100644
> --- a/NEWS.md
> +++ b/NEWS.md
> @@ -246,6 +246,9 @@ Changes to the Mercury standard library
>      - func `det_date_from_string/1` (replacement:
> `det_date_time_from_string/1`)
>      - func `date_to_string/1`       (replacement: `date_time_to_string/1`)
> 
> +* `date_time/0` and `duration/0` values now only allow for a single positive
> +  leap second.
> +
>  * The following functions and predicates have been added:
> 
>      - pred `init_date_time/8`
> @@ -1424,6 +1427,11 @@ Changes to the Mercury standard library
>      - pred `spawn_native_joinable/5`
>      - pred `join_thread/4`
> 
> +### Changes to the `time` module
> +
> +*  The `tm_sec` field of the `tm/0` type now only allows for a single positive
> +   leap second.

Both of these sentences are misleading without the qualifier "for any given minute",
since we still allow, as we have to, more than a single leap second per year.

The diff is otherwise fine, though I did not check the expected test outouts.

Zoltan.