Upstream spatie/period state of the touched files before f2bcd9f5d3

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;