Query - Access Db Returns Null After Changing Operating System Date?

I have a select statement which was returning the required values but when I changed the OS date from English(US) to English(UK), it now returns null. I believe the problem is concerned with date since in the query am selecting values where the date from the database is the same as the date in a combobox but I don't know what else I can do. It almost looks like the dates in the combox and in the database are not the same and yet the date in the combobox is actually retrieved from the database and has been returning values fine until I changed the system date format.Here's my select command:

cmd4.CommandText = _
"SELECT sum(brought_qtty), recieved_qtty from brought_coffee, centre_weigh where brought_date=#" & _
dtComb.Text.Trim & "#" & _[code].......