Recalculate Shipment time for planned shipments

Hi,

I am trying to recalculate shipment time for a shipment that is tender accepted, but is not enroute yet.

The requirement is to have a custom action on the shipment. This action must calculate if the shipment that has been tender accepted will adhere to the estimated planned delivery time on the shipment or if it will be delayed.

I tried using the recalculate estimated stop times, but the shipment needs to be enroute for this to work.

Would you have any recommendations how I can achieve this?

Many Thanks,