I have a date value for each customer id.I want to create a bin for each date on 30 days rolling basis till 36 months.Example data in the output ,I have provided till 4 months    For customer id 001 purchase date is 12AUG2014.I need to calculate a 30 days period from 12AUG2014 .That would be 11SEP2014 .So M1_Start would be 12AUG2014  and end would be 11SEP2014 .Now M2_start would be 1 day after M1_end which is 12SEP2014.Again M2_END would be 30 days after 12SEP2014 which is 12OCT2014.So on .I have to calculate till M36_start and M36_end.   Data I have  -.   cust_id           purchase_dt    001                   12-Aug-14 002                   21-Aug-14 003                    2-Sep-14 004                    4-Aug-14  005                    9-Aug-14   Data I want -    cust_id   purchase_dt   M1_start      M1_end      M2_start     M2_end      M3_start      M3_end        M4_start      M4_end 001           12-Aug-14     12-Aug-14    11-Sep-14     12-Sep-14   12-Oct-14   13-Oct-14      12-Nov-14      13-Nov-14   13-Dec-14     002          21-Aug-14     21-Aug-14    20-Sep-14    21-Sep-14   21-Oct-14    22-Oct-14    21-Nov-14      22-Nov-14   22-Dec-14  003            2-Sep-14       2-Sep-14      2-Oct-14        3-Oct-14    2-Nov-14     3-Nov-14     3-Dec-14         4-Dec-14     3-Jan-15  004            4-Aug-14      4-Aug-14       3-Sep-14      4-Sep-14    4-Oct-14      5-Oct-14     4-Nov-14           5-Nov-14     5-Dec-14  005             9-Aug-14     9-Aug-14        8-Sep-14    9-Sep-14     9-Oct-14    10-Oct-14      9-Nov-14         10-Nov-14   10-Dec-14    Thanks.Any leads will be very helpful. ... View more