my apologies, I forgot to update the pastebin link while working on this post, the pastebin originally linked didn’t have some of the query params included, most importantly the first=100 param.
I’ve edited the post to include the correct response for the linked request.
Had you actually attempted to make the rqeuest, you would find that the value of the ‘created_at’ for the oldest video is well beyond the month range
“created_at”: “2019-01-25T02:24:45Z”