Date function issue

Hi Experts,

I have an requirement related to date function in WebI.

I am working on BO 4.2 version.From the source system,I am getting the data for start date and end date.And now I need to maintain additional two more columns i.e one column is MONTHS and other column is DAYS.

Lets Say :

Start Date : 01 January,2014 = 01-01-2014

End Date : 05 April,2014 = 05-04-2014

For the above example , In the report output , it should display as :

  START DATE       END DATE             MONTHS    DAYS

  01-01-2014            05-04-2014                 3                4

Could anyone please let me know , which date function do I need to use in the formula, to achieve the above requirement?

Appreciate for your quick response.Thanks in advance