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fix: strftime() sets epoch index for %G and %s format codes #127

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Merged
atoomic merged 1 commit into from
Apr 29, 2026
Merged

fix: strftime() sets epoch index for %G and %s format codes #127

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4 changes: 3 additions & 1 deletion lib/Date/Format/Generic.pm
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Original file line number Diff line number Diff line change
Expand Up @@ -56,11 +56,13 @@ sub strftime
$epoch = timelocal(@{$time}[0..5]);

@$me = gmtime($epoch + tz_offset($tzname));
$me->[9] = $epoch;
}
else
{
@$me = @$time;
undef $epoch;
$epoch = timelocal(@$me[0..5]);
$me->[9] = $epoch;
}

_subs($me,$fmt);
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48 changes: 48 additions & 0 deletions t/strftime-epoch.t
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Original file line number Diff line number Diff line change
@@ -0,0 +1,48 @@
use strict;
use warnings;
use Test::More;
use Date::Format qw(time2str strftime);
use Time::Local qw(timegm);

# strftime() was missing $me->[9] (epoch timestamp), causing format codes
# that depend on it (%G, %s) to produce wrong results.

my $t = timegm(0, 0, 12, 28, 3, 124); # 2024-04-28 12:00:00 UTC
my @gmt = gmtime($t);

# %G (GPS week) - was returning -522 instead of 2312
is(time2str("%G", $t, "UTC"), "2312",
"time2str %G gives correct GPS week");
is(strftime("%G", @gmt, "UTC"), "2312",
"strftime %G with timezone gives correct GPS week");

# %s (epoch seconds) - strftime with localtime should match time2str
my @lt = localtime($t);
is(time2str("%s", $t), strftime("%s", @lt),
"strftime %s (localtime, no tz) matches time2str %s");

# GPS epoch boundary via strftime
my $gps_epoch = 315964800;
my @gps_gmt = gmtime($gps_epoch);
is(strftime("%G", @gps_gmt, "UTC"), "0",
"strftime %G at GPS epoch is week 0");

my @week1_gmt = gmtime($gps_epoch + 7 * 86400);
is(strftime("%G", @week1_gmt, "UTC"), "1",
"strftime %G one week after GPS epoch is week 1");

# Verify strftime and time2str agree on %G for several dates
for my $pair (
[timegm(0, 0, 0, 6, 0, 80), "0", "GPS epoch"],
[timegm(0, 0, 0, 13, 0, 80), "1", "start of week 1"],
[936709362, "1026", "Sep 7, 1999"],
) {
my ($epoch, $expected, $label) = @$pair;
my @g = gmtime($epoch);
is(strftime("%G", @g, "UTC"), $expected,
"strftime %G: $label");
is(time2str("%G", $epoch, "UTC"), $expected,
"time2str %G: $label (cross-check)");
}

done_testing;
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