If you are just working with due dates, you can perform a find that uses a date range such as 1/1/2012...1/31/2012 to find all records where the date falls in a given interval. (Used MMDDYYYY format here.)
This assumes that your due date fields are of type date when you check them in Manage | database | fields.
Thanks for your reply however on this occasion it did not help, let me explain differently.
I have a created a report that shows a list of items on site that have to be serviced annually and I have created a field on the report that shows the date an item is due for recharging but I only want to show dates that fall within two dates i.e. next inspection due (this would be any item due for recharging after this date) and next service date (this would be any item due for recharging before this date) if an inspection is due in January any equipment with a recharge date between January 2012 and January 2012 will show these dates on the report but also showing all other items without the recharge date. Thanks Robin.
From what you have posted, I don't see any reason why using a date range would not work for you.