Need delivery date field added to shopping cart page.
Customer is asked to fill this on the shopping cart page if the date is less than 30 days from today then they carry on to complete transaction. And a message is displayed under the delivery date, this message is set in the admin panel.
If the date is more than 31 days then they only pay 25% percent (this value is defined in the admin panel) This should be reflected in backend and invoice.
For Example if the basket value is $100
Then on checkout they only pay $25
and this will be displayed as
Advance payment $25
Balance remaining $75
Also needs to not allow delivery dates in certain ranges, ranges can be set from admin.