On 23/11/2025 05:43, Jeffery Palm wrote:
Hi Padraig,
Thanks for the feedback.
I was able to get back to this and have a look at getting this inconsistency
resolved, and I was able to find a change that seems to resolve this
inconsistency.
It is still correctly parsing the timezone with AM/PM:
$ ./src/date --debug -d '2024-01-01 8:00:00PM -0500'
date: parsed date part: (Y-M-D) 2024-01-01
date: parsed time part: 08:00:00pm UTC-05
date: input timezone: parsed date/time string (-05)
date: using specified time as starting value: '20:00:00'
date: starting date/time: '(Y-M-D) 2024-01-01 20:00:00 TZ=-05'
date: '(Y-M-D) 2024-01-01 20:00:00 TZ=-05' = 1704157200 epoch-seconds
date: timezone: system default
date: final: 1704157200.000000000 (epoch-seconds)
date: final: (Y-M-D) 2024-01-02 01:00:00 (UTC)
date: final: (Y-M-D) 2024-01-01 17:00:00 (UTC-08)
date: output format: ‘%a %d %b %Y %T %Z’
Mon 01 Jan 2024 17:00:00 PST
And will now correctly prioritize time offset with a ime unit is specified,
both with AM/PM and without:
$ ./src/date --debug -d '2024-01-01 8:00:00 -5 days'
date: parsed date part: (Y-M-D) 2024-01-01
date: parsed relative part: -5 day(s)
date: parsed time part: 08:00:00
date: input timezone: system default
date: using specified time as starting value: '08:00:00'
date: starting date/time: '(Y-M-D) 2024-01-01 08:00:00'
date: warning: when adding relative days, it is recommended to specify noon
date: after date adjustment (+0 years, +0 months, -5 days),
date: new date/time = '(Y-M-D) 2023-12-27 08:00:00'
date: '(Y-M-D) 2023-12-27 08:00:00' = 1703692800 epoch-seconds
date: timezone: system default
date: final: 1703692800.000000000 (epoch-seconds)
date: final: (Y-M-D) 2023-12-27 16:00:00 (UTC)
date: final: (Y-M-D) 2023-12-27 08:00:00 (UTC-08)
date: output format: ‘%a %d %b %Y %T %Z’
Wed 27 Dec 2023 08:00:00 PST
$ ./src/date --debug -d '2024-01-01 8:00:00AM -5 days'
date: parsed date part: (Y-M-D) 2024-01-01
date: parsed relative part: -5 day(s)
date: parsed time part: 08:00:00
date: input timezone: system default
date: using specified time as starting value: '08:00:00'
date: starting date/time: '(Y-M-D) 2024-01-01 08:00:00'
date: warning: when adding relative days, it is recommended to specify noon
date: after date adjustment (+0 years, +0 months, -5 days),
date: new date/time = '(Y-M-D) 2023-12-27 08:00:00'
date: '(Y-M-D) 2023-12-27 08:00:00' = 1703692800 epoch-seconds
date: timezone: system default
date: final: 1703692800.000000000 (epoch-seconds)
date: final: (Y-M-D) 2023-12-27 16:00:00 (UTC)
date: final: (Y-M-D) 2023-12-27 08:00:00 (UTC-08)
date: output format: ‘%a %d %b %Y %T %Z’
Wed 27 Dec 2023 08:00:00 PST
And the coreutils complete testsuite is passing:
============================================================================
Testsuite summary for GNU coreutils 9.9.31-1d58e
============================================================================
# TOTAL: 575
# PASS: 518
# SKIP: 57
# XFAIL: 0
# FAIL: 0
# XPASS: 0
# ERROR: 0
============================================================================
Below is the full patch:
diff --git a/lib/parse-datetime.y b/lib/parse-datetime.y
index 6c52cd2c4c..71f8b9ae0e 100644
--- a/lib/parse-datetime.y
+++ b/lib/parse-datetime.y
@@ -573,8 +573,8 @@ debug_print_relative_time (char const *item, parser_control
const *pc)
%parse-param { parser_control *pc }
%lex-param { parser_control *pc }
-/* This grammar has 31 shift/reduce conflicts. */
-%expect 31
+/* This grammar has 40 shift/reduce conflicts. */
+%expect 40
%union
{
@@ -681,17 +681,17 @@ iso_8601_datetime:
;
time:
- tUNUMBER tMERIDIAN
+ tUNUMBER tMERIDIAN o_zone_offset
{
set_hhmmss (pc, $1.value, 0, 0, 0);
pc->meridian = $2;
}
- | tUNUMBER ':' tUNUMBER tMERIDIAN
+ | tUNUMBER ':' tUNUMBER tMERIDIAN o_zone_offset
{
set_hhmmss (pc, $1.value, $3.value, 0, 0);
pc->meridian = $4;
}
- | tUNUMBER ':' tUNUMBER ':' unsigned_seconds tMERIDIAN
+ | tUNUMBER ':' tUNUMBER ':' unsigned_seconds tMERIDIAN o_zone_offset
{
set_hhmmss (pc, $1.value, $3.value, $5.tv_sec, $5.tv_nsec);
pc->meridian = $6;
@@ -720,6 +720,11 @@ iso_8601_time:
o_zone_offset:
/* empty */
| zone_offset
+ | relunit_snumber
+ {
+ if (! apply_relative_time (pc, $1, 1)) YYABORT;
+ debug_print_relative_time (_("relative"), pc);
+ }
;
zone_offset:
diff --git a/tests/test-parse-datetime.c b/tests/test-parse-datetime.c
index 23c8598a6f..8bfb7210d6 100644
--- a/tests/test-parse-datetime.c
+++ b/tests/test-parse-datetime.c
@@ -334,6 +334,31 @@ main (_GL_UNUSED int argc, char **argv)
ASSERT (result.tv_sec == result2.tv_sec
&& result.tv_nsec == result2.tv_nsec);
+ /* Check that timeone works with AM/PM */
+ p = "2024-01-01 8PM -08:00";
+ expected.tv_sec = 1704168000;
+ expected.tv_nsec = 0;
+ ASSERT (parse_datetime (&result, p, NULL));
+ LOG (p, expected, result);
+ ASSERT (expected.tv_sec == result.tv_sec
+ && expected.tv_nsec == result.tv_nsec);
+
+ /* Check that date offset is preferred to timezone */
+ p = "2024-01-01 8PM -5 days";
+ expected.tv_sec = 1703725200;
+ expected.tv_nsec = 0;
+ ASSERT (parse_datetime (&result, p, NULL));
+ LOG (p, expected, result);
+ ASSERT (expected.tv_sec == result.tv_sec
+ && expected.tv_nsec == result.tv_nsec);
+
+ p = "2024-01-01 20:00 -5 days";
+ expected.tv_sec = 1703725200;
+ expected.tv_nsec = 0;
+ ASSERT (parse_datetime (&result, p, NULL));
+ LOG (p, expected, result);
+ ASSERT (expected.tv_sec == result.tv_sec
+ && expected.tv_nsec == result.tv_nsec);
/* TZ out of range should cause parse_datetime failure */
now.tv_sec = SOME_TIMEPOINT + 4711;
Regards.
Jeff
On Tue, 29 Jul 2025 at 04:22, Pádraig Brady <[email protected]
<mailto:[email protected]>> wrote:
On 29/07/2025 06:02, Jeffery Palm wrote:
> I took a look at this bug, and believe I have a patch that will resolve
it.
>
> $ ../src/date --debug -d '2024-01-01 8:00:00PM -0500'
> date: parsed date part: (Y-M-D) 2024-01-01
> date: parsed time part: 08:00:00pm UTC-05
> date: input timezone: parsed date/time string (-05)
> date: using specified time as starting value: '20:00:00'
> date: starting date/time: '(Y-M-D) 2024-01-01 20:00:00 TZ=-05'
> date: '(Y-M-D) 2024-01-01 20:00:00 TZ=-05' = 1704157200 epoch-seconds
> date: timezone: system default
> date: final: 1704157200.000000000 (epoch-seconds)
> date: final: (Y-M-D) 2024-01-02 01:00:00 (UTC)
> date: final: (Y-M-D) 2024-01-01 17:00:00 (UTC-08)
> date: output format: ‘%a %d %b %Y %T %Z’
> Mon 01 Jan 2024 17:00:00 PST
>
>
> And I was able to run the coreutils testsuite with no tests failing:
>
>
============================================================================
> Testsuite summary for GNU coreutils 9.7.174-083f8
>
============================================================================
> # TOTAL: 533
> # PASS: 476
> # SKIP: 57
> # XFAIL: 0
> # FAIL: 0
> # XPASS: 0
> # ERROR: 0
>
============================================================================
>
> Are there any other tests/changes I should consider for this?
>
>
> Below is the patch for the changes I made for this, including a new
> testcase for AM/PM with timezone.
>
>
> --- a/lib/parse-datetime.y
> +++ b/lib/parse-datetime.y
> @@ -592,7 +592,7 @@ debug_print_relative_time (char const *item,
> parser_control const *pc)
> %token tYEAR_UNIT tMONTH_UNIT tHOUR_UNIT tMINUTE_UNIT tSEC_UNIT
> %token <intval> tDAY_UNIT tDAY_SHIFT
>
> -%token <intval> tDAY tDAYZONE tLOCAL_ZONE tMERIDIAN
> +%token <intval> tDAY tDAYZONE tLOCAL_ZONE tMERIDIAN tMERIDIAN_WITH_ZONE
> %token <intval> tMONTH tORDINAL tZONE
>
> %token <textintval> tSNUMBER tUNUMBER
> @@ -698,6 +698,27 @@ time:
> set_hhmmss (pc, $1.value, $3.value, $5.tv_sec, $5.tv_nsec);
> pc->meridian = $6;
> }
> + | tUNUMBER tMERIDIAN_WITH_ZONE tSNUMBER o_colon_minutes
> + {
> + set_hhmmss (pc, $1.value, 0, 0, 0);
> + pc->meridian = $2;
> + pc->zones_seen++;
> + if (! time_zone_hhmm (pc, $3, $4)) YYABORT;
> + }
> + | tUNUMBER ':' tUNUMBER tMERIDIAN_WITH_ZONE tSNUMBER o_colon_minutes
> + {
> + set_hhmmss (pc, $1.value, $3.value, 0, 0);
> + pc->meridian = $4;
> + pc->zones_seen++;
> + if (! time_zone_hhmm (pc, $5, $6)) YYABORT;
> + }
> + | tUNUMBER ':' tUNUMBER ':' unsigned_seconds tMERIDIAN_WITH_ZONE
> tSNUMBER o_colon_minutes
> + {
> + set_hhmmss (pc, $1.value, $3.value, $5.tv_sec, $5.tv_nsec);
> + pc->meridian = $6;
> + pc->zones_seen++;
> + if (! time_zone_hhmm (pc, $7, $8)) YYABORT;
> + }
> | iso_8601_time
> ;
>
> @@ -1527,14 +1548,19 @@ yylex (union YYSTYPE *lvalp, parser_control *pc)
>
> *p = '\0';
> tp = lookup_word (pc, buff);
> - if (! tp)
> + if (tp)
> {
> - if (debugging (pc))
> - dbg_printf (_("error: unknown word '%s'\n"), buff);
> - return '?';
> + lvalp->intval = tp->value;
> + if (tp->type == tMERIDIAN)
> + {
> + char const *p = pc->input;
Better to use a non shadowing name here ^
> + while (*p && c_isspace (*p))
> + p++;
> + if (*p == '-' || *p == '+')
> + return tMERIDIAN_WITH_ZONE;
> + }
> + return tp->type;
> }
> - lvalp->intval = tp->value;
> - return tp->type;
> }
>
> if (c != '(')
> diff --git a/tests/test-parse-datetime.c b/tests/test-parse-datetime.c
> index 546b383c55..9766ed7a13 100644
> --- a/tests/test-parse-datetime.c
> +++ b/tests/test-parse-datetime.c
> @@ -335,6 +335,15 @@ main (_GL_UNUSED int argc, char **argv)
> ASSERT (result.tv_sec == result2.tv_sec
> && result.tv_nsec == result2.tv_nsec);
>
> + /* Check that timeone works with AM/PM */
> + p = "2024-01-01 8PM -08:00";
> + expected.tv_sec = 1704168000;
> + expected.tv_nsec = 0;
> + ASSERT (parse_datetime (&result, p, NULL));
> + LOG (p, expected, result);
> + ASSERT (expected.tv_sec == result.tv_sec
> + && expected.tv_nsec == result.tv_nsec);
> +
>
> /* TZ out of range should cause parse_datetime failure */
> now.tv_sec = SOME_TIMEPOINT + 4711;
Thanks for looking at this.
This changes relative handling unfortunately:
$ src/date --debug -d '2024-01-01 8:00:00PM -5 days'
date: parsed date part: (Y-M-D) 2024-01-01
date: parsed time part: 08:00:00pm UTC-05
date: parsed relative part: +1 day(s)
...
Wed 03 Jan 2024 01:00:00 GMT
$ date --debug -d '2024-01-01 8:00:00PM -5 days'
date: parsed date part: (Y-M-D) 2024-01-01
date: parsed time part: 08:00:00pm
date: parsed relative part: -5 day(s)
...
Wed 27 Dec 2023 20:00:00 GMT
Now there is an existing ambiguity here,
where the AM/PM induces the relative interpretation:
$ date --debug -d '2024-01-01 8:00:00PM -5 days'
date: parsed date part: (Y-M-D) 2024-01-01
date: parsed time part: 08:00:00pm
date: parsed relative part: -5 day(s)
$ date --debug -d '2024-01-01 8:00:00 -5 days'
date: parsed date part: (Y-M-D) 2024-01-01
date: parsed time part: 08:00:00 UTC-05
date: parsed relative part: +1 day(s)
BTW https://bugs.gnu.org/79078 <https://bugs.gnu.org/79078> was a recent
bug report
along the same lines of the relative part being unexpectedly
considered as a timezone offset
Now I agree we're already inconsistent in this regard, but I'm sure
folks are relying on the AM/PM inducing a relative interpretation.
If we were trying to make all this more consistent, IMHO
we should change things so that we always interpret +|-<int>
<days|minutes|...>
as a relative adjustment, whereas your change does the opposite for the
AM/PM case.
Thanks for looking at this again.
I've attached the diff in case others want to more easily test.
I see that the unadorned number is still taken as a timezone which is good
for compat (and would be good to add to tests I think):
$ src/date --debug -d '2024-01-01 20:00 -5'
date: parsed date part: (Y-M-D) 2024-01-01
date: parsed time part: 20:00:00 UTC-05
thanks,
Padraig
diff --git a/lib/parse-datetime.y b/lib/parse-datetime.y
index 6c52cd2c4c..71f8b9ae0e 100644
--- a/lib/parse-datetime.y
+++ b/lib/parse-datetime.y
@@ -573,8 +573,8 @@ debug_print_relative_time (char const *item, parser_control const *pc)
%parse-param { parser_control *pc }
%lex-param { parser_control *pc }
-/* This grammar has 31 shift/reduce conflicts. */
-%expect 31
+/* This grammar has 40 shift/reduce conflicts. */
+%expect 40
%union
{
@@ -681,17 +681,17 @@ iso_8601_datetime:
;
time:
- tUNUMBER tMERIDIAN
+ tUNUMBER tMERIDIAN o_zone_offset
{
set_hhmmss (pc, $1.value, 0, 0, 0);
pc->meridian = $2;
}
- | tUNUMBER ':' tUNUMBER tMERIDIAN
+ | tUNUMBER ':' tUNUMBER tMERIDIAN o_zone_offset
{
set_hhmmss (pc, $1.value, $3.value, 0, 0);
pc->meridian = $4;
}
- | tUNUMBER ':' tUNUMBER ':' unsigned_seconds tMERIDIAN
+ | tUNUMBER ':' tUNUMBER ':' unsigned_seconds tMERIDIAN o_zone_offset
{
set_hhmmss (pc, $1.value, $3.value, $5.tv_sec, $5.tv_nsec);
pc->meridian = $6;
@@ -720,6 +720,11 @@ iso_8601_time:
o_zone_offset:
/* empty */
| zone_offset
+ | relunit_snumber
+ {
+ if (! apply_relative_time (pc, $1, 1)) YYABORT;
+ debug_print_relative_time (_("relative"), pc);
+ }
;
zone_offset:
