Can I can record "N/A" as planned start date when closing a requsition?

Summary:

we want to record "Planned start date" as blank or to "N/a" when filling a requisition with an candidate. Because in some cases start date is not defined when candidate accepts the offer. We want to add this information when HR is converting candidate from Pending worker.

Content (required):

Version (include the version you are using, if applicable):

22D

Code Snippet (add any code snippets that support your topic, if applicable):