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vb.net - Convert a string to a datetime

I am developing asp.net site using vb framework 3.5.

Im having difficulties converting string data into Date I tried using cdate function,

I have a variable sdate which is a string variable and date is stored in it which comes from textbox as dd/mm/yyyy now i want to convert this string into a Date variable as i need to perform the operations as Add a day or Subtract a day.

Please guide me how to go about this. i get the error on 3rd line as,String was not recognized as a valid DateTime. I have tried to do as follows but the error comes

Dim sdate As String 
Dim expenddt As Date
expenddt = Date.Parse(edate)
expenddt = expenddt.AddDays(-1)

But i get the error as

Conversion from String to type Date is not valid.

How can I get a Date from the string?

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You should have to use Date.ParseExact or Date.TryParseExact with correct format string.

 Dim edate = "10/12/2009"
 Dim expenddt As Date = Date.ParseExact(edate, "dd/MM/yyyy", 
            System.Globalization.DateTimeFormatInfo.InvariantInfo)

OR

 Dim format() = {"dd/MM/yyyy", "d/M/yyyy", "dd-MM-yyyy"}
 Dim expenddt As Date = Date.ParseExact(edate, format,  
     System.Globalization.DateTimeFormatInfo.InvariantInfo, 
     Globalization.DateTimeStyles.None)

OR

Dim format() = {"dd/MM/yyyy", "d/M/yyyy", "dd-MM-yyyy"}
Dim expenddt As Date
Date.TryParseExact(edate, format, 
    System.Globalization.DateTimeFormatInfo.InvariantInfo, 
    Globalization.DateTimeStyles.None, expenddt)

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