Safer to use ->sub when subtracting dates instead of adding negative numbers.

Author: lonnieezell

system/I18n/Time.php

@@ -839,7 +839,7 @@ public function subSeconds(int $seconds)
 	{
 		$time = clone($this);
 
-		return $time->add(DateInterval::createFromDateString("-{$seconds} seconds"));
+		return $time->sub(DateInterval::createFromDateString("{$seconds} seconds"));
 	}
 
 	/**
@@ -853,7 +853,7 @@ public function subMinutes(int $minutes)
 	{
 		$time = clone($this);
 
-		return $time->add(DateInterval::createFromDateString("-{$minutes} minutes"));
+		return $time->sub(DateInterval::createFromDateString("{$minutes} minutes"));
 	}
 
 	/**
@@ -867,7 +867,7 @@ public function subHours(int $hours)
 	{
 		$time = clone($this);
 
-		return $time->add(DateInterval::createFromDateString("-{$hours} hours"));
+		return $time->sub(DateInterval::createFromDateString("{$hours} hours"));
 	}
 
 	/**
@@ -881,7 +881,7 @@ public function subDays(int $days)
 	{
 		$time = clone($this);
 
-		return $time->add(DateInterval::createFromDateString("-{$days} days"));
+		return $time->sub(DateInterval::createFromDateString("{$days} days"));
 	}
 
 	/**
@@ -895,7 +895,7 @@ public function subMonths(int $months)
 	{
 		$time = clone($this);
 
-		return $time->add(DateInterval::createFromDateString("-{$months} months"));
+		return $time->sub(DateInterval::createFromDateString("{$months} months"));
 	}
 
 	/**
@@ -909,7 +909,7 @@ public function subYears(int $years)
 	{
 		$time = clone($this);
 
-		return $time->add(DateInterval::createFromDateString("-{$years} years"));
+		return $time->sub(DateInterval::createFromDateString("{$years} years"));
 	}
 
 	//--------------------------------------------------------------------