[RESOLVED] convert text to dd/mm/yyyy format

I'm trying to convert the "29/09/2009" string to date format dd/mm/yyyy

I'm using visual studio 2008, and i've tried the following:

dim sdate as string
sdate = "29/09/2009"

mydate = DateTime.Parse(sDate, Globalization.CultureInfo.CreateSpecificCulture("el-GR"))

and

mydate = Date.Parse(sDate).ToShortDateString()

and i always get #9/29/2009# instead of #29/09/2009# that i want

Any help please?

Hey,

You can create a string representation of a DateTime object using String.Format:

http://msdn.microsoft.com/en-us/library/fht0f5be.aspx

Scroll to the bottom of that page, there are lots of examples!

Hope that helps!!

Gary

You can't just do this?

Code:

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Dim myDate As New Date("29/09/2009")
myDate.ToString("dd/MM/yyyy")

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Quote:

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Originally Posted by tkoletsis

I'm trying to convert the "29/09/2009" string to date format dd/mm/yyyy

I'm using visual studio 2008, and i've tried the following:

dim sdate as string
sdate = "29/09/2009"

mydate = DateTime.Parse(sDate, Globalization.CultureInfo.CreateSpecificCulture("el-GR"))

and

mydate = Date.Parse(sDate).ToShortDateString()

and i always get #9/29/2009# instead of #29/09/2009# that i want

Any help please?

---

A Date is a Date is a Date. Dates don't have formats because they are binary values. Only string representations of dates have format. When you see #9/29/2009# that does NOT mean that your Date has that specific format. That's simply how VS represents Date literals. The value of the date is the value of the date.

Consider this. If you were to write this code:

vb.net Code:

Dim number As Integer = &HFF

and the you check the value of the variable, VS would tell you that the value was 255. Does that mean that the number has a decimal format instead of a hexadecimal format? Of course not. The number is stored in the computer in binary form, as is everything. 255 is just the way that VS represents the numeric literal.

Dates are the same. A Date is just a number stored in the computer in binary form. The number represents a number of milliseconds since a specific point in time. How can that have any format? A Date is simply a value that represents a point in time. Format is ONLY an issue when you want to display that value, at which point you need to convert it to a string, at which point you need to decide what format to use.

Ok i agree, but i still have problem with the following code:

Dim rows As DataRow() = dt.Select("[DateIn] = #" & tmpDate & "#")

I get that exception there:

System.FormatException was unhandled
Message="String was not recognized as a valid DateTime."
Source="mscorlib"
StackTrace:
at System.DateTimeParse.Parse(String s, DateTimeFormatInfo dtfi, DateTimeStyles styles) at System.Data.ConstNode..ctor(DataTable table, ValueType type, Object constant, Boolean fParseQuotes) at System.Data.ExpressionParser.Parse() at System.Data.DataExpression..ctor(DataTable table, String expression, Type type) at System.Data.Select..ctor(DataTable table, String filterExpression, String sort, DataViewRowState recordStates) at System.Data.DataTable.Select(String filterExpression)

etc...

tmpDate has the value: #2/13/2009#
Datein has the value: #2/13/2009#

My regional settings have the format dd/mm/yyyy

What can I do?

Quote:

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Originally Posted by jmcilhinney

A Date is a Date is a Date. Dates don't have formats because they are binary values. Only string representations of dates have format. When you see #9/29/2009# that does NOT mean that your Date has that specific format. That's simply how VS represents Date literals. The value of the date is the value of the date.

Consider this. If you were to write this code:

vb.net Code:

Dim number As Integer = &HFF

and the you check the value of the variable, VS would tell you that the value was 255. Does that mean that the number has a decimal format instead of a hexadecimal format? Of course not. The number is stored in the computer in binary form, as is everything. 255 is just the way that VS represents the numeric literal.

Dates are the same. A Date is just a number stored in the computer in binary form. The number represents a number of milliseconds since a specific point in time. How can that have any format? A Date is simply a value that represents a point in time. Format is ONLY an issue when you want to display that value, at which point you need to convert it to a string, at which point you need to decide what format to use.

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As I said, Date values themselves don't have a format but when you convert a Date to a String or vice versa, THAT is when format is important. In your case, when you use the DataTable.Select method you MUST specify dates in M/dd/yyyy format. As such, you can do this:

vb.net Code:

Dim rows As DataRow() = dt.Select("[DateIn] = #" & tmpDate.ToString("M/dd/yyyy") & "#")

or my preference would be:

vb.net Code:

Dim rows As DataRow() = dt.Select(String.Format("[DateIn] = #{0:M/dd/yyyy}#", tmpDate))

Hopefully this shows why you need to provide the full story when you first post. If we know exactly what you're trying to do then we can provide the exact solution. If you only provide half the story then you'll likely only get half answers. WHY you're trying to do what you're trying to do is usually just as important as WHAT you're trying to do.

Thank you, your help was very important

Quote:

---

Originally Posted by jmcilhinney

As I said, Date values themselves don't have a format but when you convert a Date to a String or vice versa, THAT is when format is important. In your case, when you use the DataTable.Select method you MUST specify dates in M/dd/yyyy format. As such, you can do this:

vb.net Code:

Dim rows As DataRow() = dt.Select("[DateIn] = #" & tmpDate.ToString("M/dd/yyyy") & "#")

or my preference would be:

vb.net Code:

Dim rows As DataRow() = dt.Select(String.Format("[DateIn] = #{0:M/dd/yyyy}#", tmpDate))

Hopefully this shows why you need to provide the full story when you first post. If we know exactly what you're trying to do then we can provide the exact solution. If you only provide half the story then you'll likely only get half answers. WHY you're trying to do what you're trying to do is usually just as important as WHAT you're trying to do.

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Hi there i have the following code for a hotel management system and whenever i execute the program i get the following error

String was not recognized as a valid Date Time.

Can you help????

Code:

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Private Sub txtDays_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtDays.TextChanged
        Dim tmpDate As Date

        tmpDate = dtpDateIn.Value

        If txtAdults.Tag = "" Then Exit Sub

        ExecNonQuery("DELETE [DateIn] " & "FROM [Rate_Per_Period] " & "WHERE [DateIn]>#" & dtpDateOut.Value.AddDays(-1) & "#")

        Dim intAdults As Short

        If txtAdults.Text = "" Then Exit Sub

        If CDbl(txtAdults.Text) = hsAdults.Minimum Then
            intAdults = 0
        Else
            intAdults = CShort(txtAdults.Text) - hsAdults.Minimum
        End If

        Dim qry As String = "SELECT * FROM Rate_Per_Period WHERE FolioNumber = '" & txtFolioNumber.Text & "' ORDER BY DateIn"

        Dim cnHotel As OleDbConnection = New OleDbConnection(cnString)

        Try
            Dim da As New OleDbDataAdapter()
            da.SelectCommand = New OleDbCommand(qry, cnHotel)

            Dim cb As OleDbCommandBuilder = New OleDbCommandBuilder(da)

            Dim ds As New DataSet()
            da.Fill(ds, "Rate_Per_Period")

            Dim dt As DataTable = ds.Tables("Rate_Per_Period")

            Dim newRow As DataRow

            Do Until tmpDate > dtpDateOut.Value.AddDays(-1)
                Dim rows As DataRow() = dt.Select("[DateIn] = #" & tmpDate & "#")
             
                If rows.Count = 0 Then
                    newRow = dt.NewRow()

                    newRow("FolioNumber") = txtFolioNumber.Text
                    newRow("DateIn") = tmpDate
                    newRow("RoomNumber") = txtRoomNumber.Text
                    newRow("RateTypeID") = cboRateType.SelectedValue
                    newRow("Rate") = txtRate.Text
                    newRow("Adults") = CDbl(txtAdults.Tag) * intAdults
                    newRow("Childrens") = CDbl(toMoney(txtChildrens.Tag)) * toNumber(txtChildrens.Text)

                    dt.Rows.Add(newRow)
                End If
                tmpDate = System.DateTime.FromOADate(tmpDate.ToOADate + 1)
            Loop

            da.Update(ds, "Rate_Per_Period")
        Catch ex As OleDbException
            MsgBox(ex.ToString)
        Finally
            cnHotel.Close()
        End Try
    End Sub

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Quote:

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Originally Posted by dgichane

Hi there i have the following code for a hotel management system and whenever i execute the program i get the following error

String was not recognized as a valid Date Time.

Can you help????

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If you're going to post to an existing thread then you should at least read it first. Post #6 addresses that specifically, so the answer is already there and you simply ignored it.