Sum costs for a month and year using sumifs

Hello All,

I am trying to calculate the travel costs for a given month and year using the sumifs function but am either getting errors or a value of zero. Here are the formulas I've tried:

=SUMIFS(plant1.travel.costs,plant1.travel.dates,MONTH(BD1),plant1.travel.dates,YEAR(BD1))

=SUMIFS(plant1.travel.costs,month(plant1.travel.dates),MONTH(BD1),year(plant1.travel.dates),YEAR(BD1))

plant1.travel.costs is a column of costs associated with each business trip, plant1.travel.dates is a column of the dates of the start of the business trip, and BD1 is the first day of the month (ex. 10/1/2014). plant1.travel.dates and BD1 are formatted as dates.

Works great! Thanks!
Rep added!