Using Access 2000, the US Marshal Service reimburses our jail for federal prisoners we house at a daily date of $40. I need a database/report that will count the number of days per month times $40 showing each prisoners name and date of birth. The problem I've run into so far is if a prisoner came in say in the middle of May and left in the middle of June, I can't figure out how to count the days the prisoner was here for May and then how many days in June. The kicker is, the government won't pay for the last day the prisoner is here, so I need to subtract the last day of stay.I've tried date parameters and variants of [datepart], but no luck. Any suggestions would be appreciated.