Adding a new coloumn and new field in report bug

[santy143all]

Hi friend,

I am working on customization of mantis and have been working on importing calender and use it as a due date.
Succeeded in showing calender but want that value of calender should be saved in database and should be shown in different column.
I have added a field so called due date in database all that i want to fetch from input field the date and store it into it.
I am facing an error so called:

APPLICATION ERROR #203
A number was expected for eta.

Please help me with same, thanks in advance.