Impact of creating new absence type

Summary:

Hello,

I would like to change the session effective date for an absence type, however I was made aware that I am not able to change the session effective date to a backdated date. The only was to change the date is to create a new absence type. This absence type (Paternity leave absence type) is not tied to any absence plan. I would like to know if a create a new absence type, is there any impact to the old absence? Apart from creating the new absence type, do I need to update anything else?

Would appreciate anyone advice on this.