Qlikview formula related to dates

[capriconuser]

this is the data i have

			1/31/2017	2/28/2017	3/31/2017	4/30/2017	5/31/2017	6/30/2017	7/31/2017	8/31/2017	9/30/2017	10/31/2017	11/30/2017	12/31/2017
ID	Start Date	End Date	1/1/2017	2/1/2017	3/1/2017	4/1/2017	5/1/2017	6/1/2017	7/1/2017	8/1/2017	9/1/2017	10/1/2017	11/1/2017	12/1/2017
A	1-Jan-17	15-Mar-17	31	28	17	0	0	0	0	0	0	0	0	0
B	5-Jun-17	4-Aug-17	0	0	0	0	0	26	31	28	0	0	0	0
C	8-Aug-17	4-Nov-17	0	0	0	0	0	0	0	24	30	31	27	0

now in this data suppose the ID A start date is 1-Jan-2017
and end date is 15-Mar-2017

this means user A achieve policy on this specific time period so i want total days of these specific months

ie. from Jan they have 31 days then in Feb 28 days and in march 17 days .. because for jan 

he have start date 1-Jan-2017 and end date for jan is 31-Jan-2017 so here (1-31-2017)-(1-Jan-2017) +1
for Feb we have 2/28/2017 - 2/1/2017 +1
for march we have 3/31/2017-(15-March-201 )+1

In jan and feb they achieve policy full month but in march policy end in 15-March-2017 so they have remaining  17 days

now how i achieve this dates formula  through qlikview expression ?  any idea ? 

i attached qlik file 

[capriconuser]

any help please