Get highest value per month

@joschika77, you could include tags that specify the month at ingest. For example, I would write a python script that adds the months in tags based on the timestamp. You could also run 12 continuous queries for each month and output the max value into a new db. If you need to apply a CQ to historical data, you can backfill your old data by doing something similar to: Backfilling a Continuous Query?