Trigger lambda function when an S3 folder is created

I am uncertain what the correct way is to trigger a function when a new folder has been created? I have For example I have an S3 bucket that stores ElasticLoadBalancer logs from my application in the form like:

s3://logs-lamp/production/STACK1-PROD/AWSLogs/XXX/elasticloadbalancing/eu-west-2/2018/04/13/

where each folder contains the logs for that day, so when a new day is created, I would like to trigger the function?

Any advise is much appreciated