Enrol at any time - assessment due dates

Please consider this enhancement:
We have "enrol at any time" students. Due dates for assessment tasks need to be set from the date of enrolment, for example:
Task 1 - Enrol date + 30 days
Task 2 - Enrol date + 75 days
etc
When a student is enrolled, the system automatically calculates the due dates for the assessment tasks (and the associated units) using the formula [Enrol date] + specified no of days.
Can this be implemented and what would be the approx timeframe (eg 1 month, 1 year) as this is critical for us to use Axcelerate.

Thanks