How to add a delivery date picker in POS system?

[ddelafield]

We are experiencing a problem that I can't believe doesn't have an easy solution but I haven't been able to find the answer.  When we check out shipping customers at the store front on the POS system we need to select a delivery date for the order.  I can't find the option to add this and I can't believe something this basic wouldn't be in the shipping process.  Any help would be appreciated.  Thanks!