continuous episodes of insurance coverage

I am trying to construct episodes of coverage for patients in an insurance database. My episodes of coverage are continuous periods of time that a patient was enrolled in an insurance plan. This is what I have:

ID YEAR ENRIND1-ENRIND12 MEMDAYS1-MEMDAYS12
101 2008 0 0 1 1 1 1 1 1 1 1 1 1 0 0 31 30……………..31
101 2009 1 1 1 1 1 0 0 1 1 1 1 1 31 28…0 0……………31
101 2010 1 1 1 1 1 1 1 1 1 0 0 0 31 28………………0 0 0

What I want to make is two episodes of continuous coverage for this:

ID FIRST1 LAST1 FIRST2 LAST2 … FIRSTN LASTN
101 2/1/2008 5/31/2009 8/1/2009 9/30/2010

The MEMDAYS1-12 variables might be necessary to create the day for LAST1-N date variables. The FIRST1-N will always start with the first of the month.

Complications being that the duplications for IDs are necessary for other parts of the analysis and I think it will be quite fine to end up with something like this:

ID FIRST1 LAST1 FIRST2 LAST2 … FIRSTN LASTN
101 2/1/2008 5/31/2009 8/1/2009 9/30/2010
101 2/1/2008 5/31/2009 8/1/2009 9/30/2010
101 2/1/2008 5/31/2009 8/1/2009 9/30/2010

I added the FIRSTN LASTN because some people may have > 2 periods of continuous coverage.

Any assistance here is appreciated, I only wish I could repay in some way.

Thank you in advance.