src/Carbon/CarbonInterval.php
public static function getCascadeFactors()
    {
        return static::$cascadeFactors ?: [
            'milliseconds' => [Carbon::MICROSECONDS_PER_MILLISECOND, 'microseconds'],
            'seconds' => [Carbon::MILLISECONDS_PER_SECOND, 'milliseconds'],
            'minutes' => [Carbon::SECONDS_PER_MINUTE, 'seconds'],
            'hours' => [Carbon::MINUTES_PER_HOUR, 'minutes'],
            'dayz' => [Carbon::HOURS_PER_DAY, 'hours'],
            'months' => [Carbon::DAYS_PER_WEEK * Carbon::WEEKS_PER_MONTH, 'dayz'],
            'years' => [Carbon::MONTHS_PER_YEAR, 'months'],
        ];
    }
public static function getCascadeFactors()
    {
        return static::$cascadeFactors ?: [
            'milliseconds' => [Carbon::MICROSECONDS_PER_MILLISECOND, 'microseconds'],
            'seconds' => [Carbon::MILLISECONDS_PER_SECOND, 'milliseconds'],
            'minutes' => [Carbon::SECONDS_PER_MINUTE, 'seconds'],
            'hours' => [Carbon::MINUTES_PER_HOUR, 'minutes'],
            'dayz' => [Carbon::HOURS_PER_DAY, 'hours'],
            'months' => [Carbon::DAYS_PER_WEEK * Carbon::WEEKS_PER_MONTH, 'dayz'],
            'years' => [Carbon::MONTHS_PER_YEAR, 'months'],
        ];
    }
public static function getCascadeFactors ( ) { return static :: $ cascadeFactors ? : [ 'milliseconds' => [ Carbon :: MICROSECONDS_PER_MILLISECOND , 'microseconds' ] , 'seconds' => [ Carbon :: MILLISECONDS_PER_SECOND , 'milliseconds' ] , 'minutes' => [ Carbon :: SECONDS_PER_MINUTE , 'seconds' ] , 'hours' => [ Carbon :: MINUTES_PER_HOUR , 'minutes' ] , 'dayz' => [ Carbon :: HOURS_PER_DAY , 'hours' ] , 'months' => [ Carbon :: DAYS_PER_WEEK * Carbon :: WEEKS_PER_MONTH , 'dayz' ] , 'years' => [ Carbon :: MONTHS_PER_YEAR , 'months' ] , ] ; }
Mapping of units and factors for cascading.

Should only be modified by changing the factors or referenced constants.

@return array
Mapping of units and factors for cascading .