Check If Cell Is A Date

My excel worksheet is a Project Status Log with many rows and columns. My code goes through each row and sorts the projects Unique_ID by Launch Date. On the Launch & Revised (12 & 13) columns, I need to perform the following for each row (I reference Column 2 which is a Unique_ID).

Check if Revised value is populated
If yes then use Revised value else use Launch value
Check if value is a date else store Unique_ID in array Other
If the value is a date then check # of days from today to value

My problem is that if the value is not a date it does not store in array Other but may store to any of the alternate arrays I am utilizing. (I believe this is due to the string being converted to a date and then checked for date difference but don't know why this is happening.)

I have added more than the code I described in an effort to provide more understanding, so if you need more detail I can attempt to explain but right now my brain is hurting.

Do Until Sheets("Project Log").Cells(aRow, 2).Value = ""
On Error Resume Next

'Separate Top 10
If Sheets("Project Log").Cells(aRow, 3).Value = "Y" Then
a = a + 1
Redim Preserve arrT10(UBound(arrT10) + 1)
arrT10(a) = Sheets("Project Log").Cells(aRow, 2).Value
Else