As horrible as the code is to a seasoned perl developer, the task appears to be to modify it rather than rewrite it and when modifying, we are usually supposed to maintain the existing style even though we might hate it. On the other hand, there is something slightly wrong with starting one month ago and ending today because if the start date is the 1st of the month then so is the end date and likewise if the end-date is the last day of a month then so is the start date. So I would check whether the report is duplicating data for the first or last day of the month before using it as a basis for generating a two year report - it certainly looks that way. What to do next - rewrite or modify depends on that although it might not be your decision which way to go.