Amazon S3 server access logging now supports automatic date-based partitioning for log delivery. Amazon S3 server access logging provides detailed records for requests made to your S3 buckets including object size, total time, turn-around time, HTTP referer, and more. Now, with date-based partitioning, Amazon S3 automatically generates either event time or delivery time prefixes when delivering access logs to your destination bucket, which allows services like Amazon Athena, Amazon EMR, and Amazon Redshift Spectrum to improve performance and reduce cost when querying logs.
Source:: Amazon AWS