Get sales Orders between dates - vb.net

Question

How can I make a call to the Magento SOAP API v2 to get all of the sales orders between a set of dates in vb.net?
Here is what I have tried so far, but it returns 0 sales orders despite the fact that they are present.
Dim ae As associativeEntity = New associativeEntity()
ae.key = "status"
ae.value = "processing"
Dim params As filters = New filters
Dim dateFilter As complexFilter
dateFilter = New complexFilter()
dateFilter.key = "created_at"
Dim nestedFilterFrom As associativeMultiEntity = New associativeMultiEntity()
nestedFilterFrom.key = "gteq"
nestedFilterFrom.value = New String() {DateTime.Parse(fromDate).ToUniversalTime.ToString()}
dateFilter.value = nestedFilterFrom
Dim dateToFilter As complexFilter = New complexFilter()
Dim nestedFilterTo As associativeMultiEntity = New associativeMultiEntity()
nestedFilterTo.key = "lteq"
nestedFilterTo.value = New String() {DateTime.Parse(toDate).ToUniversalTime.ToString()}
dateToFilter.key = "created_at"
dateToFilter.value = nestedFilterTo
params.complex_filter = New complexFilter() {dateFilter, dateToFilter}
magentoWS.salesOrderList(sessionID, params)
I have been able to get the same code to work matching on status, like below.
Dim ae As associativeEntity = New associativeEntity
Dim params As filters = New filters()
ae.key = "status"
ae.value = "processing"
params.filter = New associativeEntity() {ae}
magentoWS.salesOrderList(sessionID, params)

Answer 1

The date format must be the following for the filters to work.
YYYY-MM-DD
I only discovered this, because that is how it was in Magento's SOAP "v2" XML Request example. It would have been nice to specify this in the documentation or in their response, but se la vie. In case anyone is interested, here is the code.
Dim ae As associativeEntity = New associativeEntity With { .key = "status", .value = "processing" }
Dim params As filters = New filters
Const createdAt As String = "created_at"
Const magentoDateTimeFormat As String = "yyyy-MM-dd"
Dim nestedFilterFrom As associativeMultiEntity =
New associativeMultiEntity With {.key = "from", .value = New String() {fromDate.ToString(magentoDateTimeFormat)}}
Dim dateFromFilter As complexFilter = New complexFilter With {.key = createdAt, .value = nestedFilterFrom}
Dim nestedFilterTo As associativeMultiEntity =
New associativeMultiEntity With {.key = "to", .value = New String() {toDate.ToString(magentoDateTimeFormat)}}
Dim dateToFilter As complexFilter = New complexFilter With {.key = createdAt, .value = nestedFilterFrom}
params.complex_filter = New complexFilter() {dateFromFilter, dateToFilter}
magentoWS.salesOrderList(sessionID, params)
It should be noted that in this case, the from and to filters are equivalent to the lteq and gteq. I found from and to to make more sense in this context but results are the same.

Answer 2

Public Function getMageOrdersListByFilter(ByVal fromDate As DateTime, ByVal toDate As DateTime) As MagentoService.salesOrderListEntity()
GetMageSessionId()
Dim f As MagentoService.filters = New MagentoService.filters
Const createdAt As String = "created_at"
Dim magentoDateTimeFormat As String = "yyyy-MM-dd"
magentoDateTimeFormat = "yyyy-MM-dd HH:mm:ss"
Dim cpf(2) As MagentoService.complexFilter
cpf(0) = New MagentoService.complexFilter With {.key = createdAt, .value = New MagentoService.associativeEntity With {.key = "from", .value = New String(fromDate.ToString(magentoDateTimeFormat))}}
'HACK FIX: http://www.magentocommerce.com/bug-tracking/issue?issue=8073
cpf(1) = New MagentoService.complexFilter With {.key = "/*fake*/created_at", .value = New MagentoService.associativeEntity With {.key = "to", .value = New String(toDate.ToString(magentoDateTimeFormat))}}
f.complex_filter = cpf
Dim oList() As MagentoService.salesOrderListEntity = Nothing
Try
oList = mage.salesOrderList(sessionId, f)
Catch ex As Exception
End Try
Return oList
End Function