string to date conversion in vb.net/asp.net vs 2010

You'll need to use the formatdatetime function and specify the format of the string, eg

Dim MyDate = FormatDateTime("01012010", "MMddyyyy")

Select allOpen in new window

here I am assuming your string is Month, Date and Year. If it is Date, Month and year you have to use

Dim MyDate = FormatDateTime("01012010", "ddMMyyyy")

Select allOpen in new window

Explanation why cDate is not working: is doesn't recognize your string as a date. Try your string like this: "01 01 2010" or "01/01/2010"

 to nepaluz:

FormatDateTime("01012010", "MMddyyyy")
 
returns ...

{"Conversion from string "01012010" to type 'Date' is not valid."}
    _HResult: -2147467262
    _message: "Conversion from string "01012010" to type 'Date' is not valid."
    Data: {System.Collections.ListDictionaryInternal}
    HelpLink: Nothing
    HResult: -2147467262
    InnerException: Nothing
    IsTransient: False
    Message: "Conversion from string "01012010" to type 'Date' is not valid."
    Source: "Microsoft.VisualBasic"
    StackTrace: "   at Microsoft.VisualBasic.CompilerServices.Conversions.ToDate(String Value)"
    TargetSite: {System.DateTime ToDate(System.String)}


to gerwinjansen:

no modification to the input string is acceptable, the date can be entered as 01011980 or 111980 so parsing isn't really an option

>>the date can be entered as 01011980 or 111980 so parsing isn't really an option
If that's the case then finding a solution will be very difficult. I suggest that you have fixed fields in your input or at least validate.

There are many different ways to do that. Here are 2 of those, assuming that you string is in the format MMddyyyy:

Dim yourDate As String = "01012010"
Dim result As Date

result = CDate(yourDate.Substring(0, 2) & "/" & yourDate.Substring(2, 2) & "/" & yourDate.Substring(4, 4))
result = DateSerial(CInt(yourDate.Substring(4, 4)), CInt(yourDate.Substring(0, 2)), CInt(yourDate.Substring(2, 2)))

Select allOpen in new window

The second one is a little more complex, but is independant of the control panel, so it might be safer to use.

If your string is ddMMyyyy, simply invert the 0,2 and 2,2 Substrings in the expressions.

My Bad. Here's one that works
Dim MyString = "01012010"
If the month is the first two characters

Dim FirstDate = New DateTime(MyString.Substring(4), MyString.Substring(0, 2), MyString.Substring(2, 2))

Select allOpen in new window

else if the month is the 3rd and 4th characters

Dim SecondDate = New DateTime(MyString.Substring(4), MyString.Substring(2, 2), MyString.Substring(0, 2))

Select allOpen in new window

thanks

I don't understand why you accept a solution that parses 01012010 because you state: "the date can be entered as 01011980 or 111980 so parsing isn't really an option"

Does the solution you accepted work for 111980 as input?