On the Sales Order line, create two columns “start date” and “end date”. Use revenue field mapping functionality and map your custom columns to revenue element start date and end date. You can use revenue field mapping to map any desired reporting dimensions.
Go back to your sales order and enter 1/1/2020 and 1/30/2020 on your line. Once you’ve billed the sales order, updated your rev arrangement and plans, you should get a rev plan that starts 1/1/2020 thru 1/30. If you bill on 1/5, the plan doesn’t get created till 1/5. If you do not want the actual plan start date to be 1/1, then you will need to change the rev rule start date source = event date (event here being bill date), keep rev rec rec end date source = element end date (what you manually entered on the sales order line).
Taking a bigger step back, NS rev recs actuals per month, so whatever happens within the same month will be recognized at month end. If you prorate across periods then this solution is fine (method = SL, using exact days or prorate first and last period)