Is it possible to add a date as a fixed field (i.e. not a datepicker) so I can use it in calculations?

I wish to have a field of type date with a fixed value of "1st October 2014" to allow me to do subsequent calculations with separate date fields whihc the user will choose the values from a date picker.

You cant set the Birth Day Picker tool to read only at this time. Nevertheless the DateTime tool does have the ability to be set to Read Only by going to it's properties:

Do let us know if you need further assistance. Thank you.