Witching hour

My little one is 6 weeks old and we have officially hit the witching hour stages. He’s honestly a good baby, but lately once 8 PM hits it’s been hell and tonight is the worst night we have had. I recently switched formula from Enfamil to Kirkland brand, do you think this could be part of it? Or is it just the phase we are in? He was an angel all day today until 8 PM and now I am at my wits end.