The current recurrence options does not allow you to specify both a recurring pattern of hours and which days it is relevant for.

For example I would like a batch-job to run every Friday with a recurrence of 3 hours. Currently if you select a specific day you cannot define other values such as which hours/minutes it should run.

The only way in standard that I am aware of to solve this is to create several batch-jobs for Friday and define different starting time for each job. Instead of 1 batch job with the flexibility to define both hours and days.

There are multiple ways this could be achieved.

1. Either the batch-job recurrence form is extended to allow more details. For example if you specify recurrence as 'hours' you would also have the option to exclude days you do not want to run the batch-job for.
2. Or the 'active period' feature is extended. 'Active period' feature currently allows you define time limitations (start time and end time) but it does not allow you to define specific days for the time limitation.

In above example you could have 1 batch job with a recurring of 3 hours and specify Friday as active day. Or you could use calendar functionality connected to batch-jobs to allow this.

This improvement would minimize the number of batch-jobs you need to set up and maintain.