Chronological Sorting Problem

I need to sort a column of data by date in Excel. The challenge is some rows show a single month (e.g. April 2013), and other show two months separated by a slash (May/June 2013). There is not much logic to which rows have the back-to-back months, so I can't do a simple find and replace. Can I use a formula or some other Excel trick to get all of the back-to-back months to fall into chronological order.

Essentially, I need a function that removes anything between a / and a number (the year).

The other challenge I am finding is that, when I create a function that gets close to the solution, the function column can't be sorted chronologically.

Can you upload an example workbook with an example of your data?

For what it's worth you could turn May/June 2013 into May 2013 using something like:
=LEFT(A1,FIND("/",A1,1)-1)&" "&RIGHT(A1,4)

perhaps you would then want to return the datevalue:
=datevalue(LEFT(A1,FIND("/",A1,1)-1)&" "&RIGHT(A1,4))

but it would depend on the format of the rest of your data..

Thanks for the response. My challenge is that there is no consistency on the double months, and I need to run this report every month. So -4 solution would work for May, but no other months. Here is the file:

monthlydata.xlsx

Thanks again for your help!

ok so some of your examples make this more difficult with having other words and things in the phrases. I think the best way might be a UDF along the lines of:

Public Function Get_month(str)
Dim count, count1
str = Split(Replace(str, "/", " "), " ")
count = 0
Do Until str(count) = "January" Or str(count) = "February" Or str(count) = "March" _
    Or str(count) = "April" Or str(count) = "May" Or str(count) = "June" _
    Or str(count) = "July" Or str(count) = "August" Or str(count) = "October" _
    Or str(count) = "October" Or str(count) = "November" Or str(count) = "December"
    count = count + 1
Loop
For count1 = LBound(str) To UBound(str)
    If Len(str(count1)) = 4 And Left(str(count1), 2) = "20" Then
        Get_month = CDate("01 " & str(count) & " " & str(count1))
        Exit Function
    End If
Next count1
End Function

Press Alt+F11 to open the vba editor, click insert-> module and then copy that code in.

Then on your worksheet, in H8 put:
=IF(ISNUMBER(A8),A8,Get_month(A8))
and copy down, you can then sort by this column.

Thanks! This works perfectly.