Index rotation at specific time of day

The currently available index rotation strategies (as of Graylog 2.3.0) support rotating indices according to number of messages, (approx.) size of indices, and after a specific duration.

Some users have the requirement to rotate indices at a specific time of day (e. g. midnight in the local timezone or every n hours starting at midnight) which cannot be modeled with the available index rotation strategies.

As a workaround, users can create a cron job which triggers index rotation via the Graylog REST API at the desired time of day, but having that functionality built-in would be preferable.