Query returning unexpected results

In my application I have a Spotlight model.

I run this query:

Spotlight::newerThan(1)->published()->inRandomOrder()->take(2)->get();

Here are the query scopes.

/**
 * Scope an article by whether or not it's published
 * 
 */
public function scopePublished($query)
{
    return $query->where('status', 'published');
}

/**
 * Only retrieve Spotlights newer than the given increment
 *
 * @param [type] $query
 * @param [type] $interval
 * @return void
 */
public function scopeNewerThan($query, $interval)
{
    return $query->where('created_at', '<=', Carbon::now()->subMonths($interval)->toDateTimeString());
}

Dumping the actual query gives this:

"select * from `spotlights` where `created_at` <= 2019-10-01 16:14:27 and `status` = published order by RAND() limit 2"

However, I have no spotlights that are newer than one month, and yet it still returns something.