diff --git a/src/PeriodTraits/PeriodGetters.php b/src/PeriodTraits/PeriodGetters.php
index 4c3808f..7ec6a7e 100644
--- a/src/PeriodTraits/PeriodGetters.php
+++ b/src/PeriodTraits/PeriodGetters.php
@@ -66,13 +66,6 @@ trait PeriodGetters
 
     public function length(): int
     {
-        // Excluding the boundaries of a period that is only a few units long can push the
-        // included start past the included end. Such a period contains nothing, which is what
-        // iterating over it yields, so its length is 0 rather than a distance measured backwards.
-        if ($this->includedStart() > $this->includedEnd()) {
-            return 0;
-        }
-
         // Length of month and year are not fixed, so we can't predict the length without iterate
         // TODO: maybe we can use cal_days_in_month ?
         if ($this->precision->equals(Precision::MONTH(), Precision::YEAR())) {
@@ -80,7 +73,7 @@ trait PeriodGetters
         }
 
         if ($this->precision->equals(Precision::HOUR(), Precision::MINUTE(), Precision::SECOND())) {
-            $length = $this->includedEnd()->getTimestamp() - $this->includedStart()->getTimestamp();
+            $length = abs($this->includedEnd()->getTimestamp() - $this->includedStart()->getTimestamp());
 
             if ($this->precision->equals(Precision::SECOND())) {
                 return $length + 1;
diff --git a/tests/BoundaryTest.php b/tests/BoundaryTest.php
index d55889d..2160dfd 100644
--- a/tests/BoundaryTest.php
+++ b/tests/BoundaryTest.php
@@ -35,11 +35,6 @@ it('length with boundaries', function ($expectedAmount, Period $period) {
     expect($period->length())->toEqual($expectedAmount);
 })->with('periods_with_amounts_of_included_dates');
 
-it('length is zero when excluding boundaries leaves nothing', function (Period $period) {
-    expect(iterator_count($period))->toEqual(0);
-    expect($period->length())->toEqual(0);
-})->with('periods_left_empty_by_excluded_boundaries');
-
 it('overlap with excluded boundaries', function () {
     $a = Period::make('2018-01-01', '2018-01-05', boundaries: Boundaries::EXCLUDE_END());
     $b = Period::make('2018-01-05', '2018-01-10');
diff --git a/tests/Datasets/Dates.php b/tests/Datasets/Dates.php
index ee7bd17..ef9154a 100644
--- a/tests/Datasets/Dates.php
+++ b/tests/Datasets/Dates.php
@@ -81,38 +81,6 @@ dataset('periods_with_amounts_of_included_dates', function () {
     yield [86362, Period::make('2018-01-01 00:00:00', '2018-01-01 23:59:22', Precision::SECOND(), Boundaries::EXCLUDE_START())];
     yield [86362, Period::make('2018-01-01 00:00:00', '2018-01-01 23:59:22', Precision::SECOND(), Boundaries::EXCLUDE_END())];
     yield [86361, Period::make('2018-01-01 00:00:00', '2018-01-01 23:59:22', Precision::SECOND(), Boundaries::EXCLUDE_ALL())];
-
-    // Excluding a boundary of a one unit long period leaves nothing behind.
-    yield [1, Period::make('2021-01-01', '2021-01-01', Precision::DAY(), Boundaries::EXCLUDE_NONE())];
-    yield [0, Period::make('2021-01-01', '2021-01-01', Precision::DAY(), Boundaries::EXCLUDE_START())];
-    yield [0, Period::make('2021-01-01', '2021-01-01', Precision::DAY(), Boundaries::EXCLUDE_END())];
-    yield [0, Period::make('2021-01-01', '2021-01-01', Precision::DAY(), Boundaries::EXCLUDE_ALL())];
-
-    yield [1, Period::make('2021-01-01 00:00:00', '2021-01-01 00:00:00', Precision::HOUR(), Boundaries::EXCLUDE_NONE())];
-    yield [0, Period::make('2021-01-01 00:00:00', '2021-01-01 00:00:00', Precision::HOUR(), Boundaries::EXCLUDE_START())];
-    yield [0, Period::make('2021-01-01 00:00:00', '2021-01-01 00:00:00', Precision::HOUR(), Boundaries::EXCLUDE_END())];
-    yield [0, Period::make('2021-01-01 00:00:00', '2021-01-01 00:00:00', Precision::HOUR(), Boundaries::EXCLUDE_ALL())];
-
-    yield [0, Period::make('2021-01-01 00:00:00', '2021-01-01 00:00:00', Precision::MINUTE(), Boundaries::EXCLUDE_ALL())];
-    yield [0, Period::make('2021-01-01 00:00:00', '2021-01-01 00:00:00', Precision::SECOND(), Boundaries::EXCLUDE_ALL())];
-
-    // A two unit long period keeps exactly one unit when one of its boundaries is excluded.
-    yield [2, Period::make('2021-01-01', '2021-01-02', Precision::DAY(), Boundaries::EXCLUDE_NONE())];
-    yield [1, Period::make('2021-01-01', '2021-01-02', Precision::DAY(), Boundaries::EXCLUDE_START())];
-    yield [1, Period::make('2021-01-01', '2021-01-02', Precision::DAY(), Boundaries::EXCLUDE_END())];
-    yield [0, Period::make('2021-01-01', '2021-01-02', Precision::DAY(), Boundaries::EXCLUDE_ALL())];
-});
-
-dataset('periods_left_empty_by_excluded_boundaries', function () {
-    yield 'day' => [Period::make('2021-01-01', '2021-01-01', Precision::DAY(), Boundaries::EXCLUDE_START())];
-    yield 'day, end excluded' => [Period::make('2021-01-01', '2021-01-01', Precision::DAY(), Boundaries::EXCLUDE_END())];
-    yield 'day, all excluded' => [Period::make('2021-01-01', '2021-01-01', Precision::DAY(), Boundaries::EXCLUDE_ALL())];
-    yield 'two days, all excluded' => [Period::make('2021-01-01', '2021-01-02', Precision::DAY(), Boundaries::EXCLUDE_ALL())];
-    yield 'hour' => [Period::make('2021-01-01 00:00:00', '2021-01-01 00:00:00', Precision::HOUR(), Boundaries::EXCLUDE_ALL())];
-    yield 'minute' => [Period::make('2021-01-01 00:00:00', '2021-01-01 00:00:00', Precision::MINUTE(), Boundaries::EXCLUDE_ALL())];
-    yield 'second' => [Period::make('2021-01-01 00:00:00', '2021-01-01 00:00:00', Precision::SECOND(), Boundaries::EXCLUDE_ALL())];
-    yield 'month' => [Period::make('2021-01-01', '2021-01-01', Precision::MONTH(), Boundaries::EXCLUDE_ALL())];
-    yield 'year' => [Period::make('2021-01-01', '2021-01-01', Precision::YEAR(), Boundaries::EXCLUDE_ALL())];
 });
 
 dataset('ceiling_dates', function () {