Marlon Ribunal has a script to split partitioned tables automatically:
So, let’s pretend it’s the month of April 2017 and this is the partition currently populated. Based on the query above, aside from the current partition bucket, we also have another available bucket month for May.
Say we want to maintain 3 available buckets at any given time. The next available bucket is May, so that means we need 2 more partitions to cover for June and July.
Read on for more, including some scripts that you can automate.