I am trying to determine if there is a missing month/year in a time series and which month/year it is? this problem can cut across years.
The start_date changes from record to record. the log dates are in the mm/01/yyyy format(always the first day of the month). end date can be today's date.


file looks like this:
id start_date cal_date
333 10/04/2000 10/01/2000
333 10/04/2000 12/01/2000
333 10/04/2000 05/01/2001
333 10/04/2000 07/01/2001
333 10/04/2000 08/01/2001
333 10/04/2000 09/01/2001
444 12/20/2000 01/01/2001
444 12/20/2000 05/01/2001
444 12/20/2000 06/01/2001
444 12/20/2000 09/01/2001

I am hoping to get the following results
333 11/01/2000
333 01/01/2001
333 02/01/2001
333 03/01/2001
333 04/01/2001
333 06/01/2001
444 02/01/2001
444 03/01/2001
444 04/01/2001
444 07/01/2001
444 08/01/2001


can anyone help?