View source for Appendix: Period Calculation

<br/>{{warning|This is only available for environments starting from version 2018.11!}}<br/>

When a document enters the archive from an external source (BilltoBox for example), you're mostly not given the choice of what to fill in for the period field. This means that those documents will enter the archive with an empty period. <br/>
To make your life a little bit easier, there's an option to automatically fill in a calculated period. This option contains of some different values to choose from:
* '''First open period''': 
* '''Invoice date or empty''':
* '''Invoice date or most recent open period''':
* '''Invoice date or oldest open period''':
* '''Most recent open period''':