New position default effective start date

Summary:

Default position effective date to 1/1/1951

Content (required):

Would love to know if there is a way to change the default effective start date when creating new positions.

Ours defaults to today's date but that causes issues when you have a requisition or offer being created from that position (eg if you future date a position you can't raise a req until that date!). So we want to default to 1/1/1951 - have managed to get it to default using page composer but then once it's submitted, it reverts back to today's date.

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