Converting Raw Text to date

Question

I am working with some raw data, I have a label which has a text "10/02/2010" I want this text to be converted to a date in this format dd/mm/yyyy

How can i do this in vb.net

Any help will be appreciated

Thanks

Answer 1

Hi Sid,

go to : Converting a string into required date format in vb.net

---

Pl. Mark/Proposed as Answer if found your solution Vote as Helpful if related to your topic. Always Motivate others by performing this Action.

Answer 2

Dim s As String = "10/02/2010"
Dim d As DateTime = DateTime.Parse(s, New Globalization.CultureInfo("en-GB"))

Note that a DateTime does not have a format - that is only materialized in a string if you convert the DateTime to a string.

--
Andrew

Answer 3

If you have a fixed format, you can use PaseExact method, where you define the exact date format, so there cannot be any ambiguities:

Dim strDate As String = "10/02/2010"
Dim [date] As DateTime = DateTime.ParseExact(strDate, "dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture)

---

Mitja

Answer 4

Les,

I do see both lines of the code in my earlier reply, and I see both lines, with a horizontal scrollbar, in Mitja's reply. Checked using Firefox and IE9 on Windows 7 x64.

Are you seeing the first or last line of my code?

Dim s As String = "10/02/2010"

Dim d As DateTime = DateTime.Parse(s, New Globalization.CultureInfo("en-GB"))

Sid: apologies for this being off-thread, but this forum has been having some issues.

--
Andrew

Answer 5

Les,

You may want to post in the Forums Issues forum instead.

--
Andrew

Answer 6

What I don't like about the  DateTime.ParseExact method is that it does what it's meant to do: You tell it in advance what culture it's supposed to be.

That's further restricting what the user can enter (assuming they're typing it in - in which case, why not use a DateTimePicker control) and, moreover, unlike DateTime.TryParse, it blows up if fails. From the MSDN page referenced:

"The format of the string representation must match the specified format exactly."

Are you going to include a way for the user to select which culture it's supposed to be in?

---

Please call me Frank :)

Answer 7

What I don't like about the DateTime.ParseExact method is that it does what it's meant to do: You tell it in advance what culture it's supposed to be.

But without knowing the culture, there is no hope of knowing what date 1/12/2012, for example, represents.

Are you going to include a way for the user to select which culture it's supposed to be in?

That isn't exactly difficult, but it appears to be beyond the scope of the original question.

--
Andrew

Answer 8

This is the same as your other question.

http://social.msdn.microsoft.com/Forums/en-US/vbgeneral/thread/52efaa4a-4d51-42cb-b448-24f4a6ba998b

The answer is the same - you need to look at how the string got into the label.   That will tell you the source of the data that you need to use as a date, and that will tell you the sort of coversion (if any) that you need to do.

Answer 9

This is the same as your other question.

http://social.msdn.microsoft.com/Forums/en-US/vbgeneral/thread/52efaa4a-4d51-42cb-b448-24f4a6ba998b

The answer is the same - you need to look at how the string got into the label.   That will tell you the source of the data that you need to use as a date, and that will tell you the sort of coversion (if any) that you need to do.

While I don't disagree per se, as stated it doesn't matter.

The post title is simply "Converting Raw Text To Date" so given that ... does it really matter the source? Maybe it's an XML file from a SOAP API or who knows what.

Like I said, I'm not disagreeing per se (and he did say he has it in a label so it had come from somewhere), but there certainly are instances where you don't really know what the source is from. The example of the XML returned from an API call - if you don't know what basis the DateTime is, then ... what?

:)

---

Please call me Frank :)

Answer 10

Addendum

For example, have a look at this which is the return data (xml) from Last.fm for a particular music album:

http://ws.audioscrobbler.com/2.0/?method=album.getinfo&api_key=b25b959554ed76058ac220b7b2e0a026&artist=Cher&album=Believe

Look for "releasedate" not too far from the top. What format is that in? Aside from looking at it and pretty well "just knowing" what it's in, how would you know? What there states the culture?

Let's just see what happens if I try to convert it (do keep in mind that I'm in the U.S.):

        Dim testDateString As String = "5 Jul 2005, 00:00"
        Dim testDate As DateTime
        '
        If DateTime.TryParse(testDateString, testDate) Then
            MessageBox.Show(testDate.ToLongDateString)
        End If

Amazing ... how did it know that! That's not the format that the text string was in but ...

Anyway, enough of that - my point in that other thread and in this one is that while you can do all sorts of things like including a specific culture or any of that, "as stated for how do you convert...", in my opinion there are some things which you have to rely on.

If it fails the test (TryParse), then investigate why but "as stated", I really don't see it as being as big a deal as others here perceive it to be.

Just my opinion, obviously. :)

---

Please call me Frank :)

Answer 11

Amazing ... how did it know that! That's not the format that the text string was in...

The characters "Jul" are a bit of a give-away. The parsing succeeds if you use either en-US or en-GB for that one. And you chose the output string format by using .ToLongDateString, which uses the current locale of the thread. No magic involved ;)

--
Andrew

Answer 12

While I don't disagree per se, as stated it doesn't matter.

That's certainly true, if you don't care whether or not the result is correct, or that it might create a runtime error when presented with an 'invalid' date.

OP hasn't stated that they are concerned about these things, but I think it's reasonable to assume they would be.  That's why OP has to go back to the source for this text string, and use that to determine if (a) no conversion is required because the original data was a date or (b) conversion from a particular format is possible or (c) it cannot be determined what conversion format should be used until many more examples are provided.

We still don't know whether the example provided was a date in February or a date in October.

Answer 13

The characters "Jul" are a bit of a give-away. The parsing succeeds if you use either en-US or en-GB for that one. And you chose the output string format by using .ToLongDateString, which uses the current locale of the thread. No magic involved ;)

--
Andrew

Right! Which was my entire point!

As stated - how to convert text to a date - who knows what format it's in? AS STATED ... you have to rely on something or we go the full route and have a setup routine like I said earlier about setting the culture and all that.

:)

---

Please call me Frank :)

Answer 14

Ok Acamar ... I think you're still missing my point, but that's fine too. :)

---

Please call me Frank :)

Answer 15

This works too

Imports System
Imports System.IO
Imports System.Text

Public Class Form1

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Label1_Click(sender As Object, e As EventArgs) Handles Label1.Click

    End Sub

    Private Sub Label2_Click(sender As Object, e As EventArgs) Handles Label2.Click

    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim Date1 As String = Label1.Text
        Dim Date1Array(Date1.Length) As Char

        Using Date1StringReader As StringReader = New StringReader(Date1)
            Date1StringReader.Read(Date1Array, 0, 10) '10 characters in Date1Array
        End Using

        Dim Date1StringBuilder As New StringBuilder("")
        Using Date1StringWriter As StringWriter = New StringWriter(Date1StringBuilder)
            ' Write ten characters from the array into the StringBuilder.
            Date1StringWriter.Write(Date1Array, 3, 1)
            Date1StringWriter.Write(Date1Array, 4, 1)
            Date1StringWriter.Write(Date1Array, 5, 1)
            Date1StringWriter.Write(Date1Array, 0, 1)
            Date1StringWriter.Write(Date1Array, 1, 1)
            Date1StringWriter.Write(Date1Array, 2, 1)
            Date1StringWriter.Write(Date1Array, 6, 1)
            Date1StringWriter.Write(Date1Array, 7, 1)
            Date1StringWriter.Write(Date1Array, 8, 1)
            Date1StringWriter.Write(Date1Array, 9, 1)

            Label2.Text = Date1StringBuilder.ToString

        End Using

    End Sub

End Class

---

You've taught me everything I know but not everything you know.

Answer 16

This works too

No it doesn't.  OP's requirement was "...to be converted to a date".  Nowhere does your code convert anything to a date - you are simply manipulating some strings.

Answer 17

I'm not sure what the difference is, it represents the date as 02/10/2012

---

You've taught me everything I know but not everything you know.

Answer 18

Sid,

If somebody else wrote this, than sorry. 

However, a date is not a string, it is a struct with many methods to convert a date but only one data item which is an Int64 with the name Tick 

You cannot set it by an = because it is read only and therefore only construct with phrases like

dim x = new DateTime(2012,9,23)

Because it by using one of it endless methods (very important the overloaded ToString) you can show it in every string format you want, you don't convert a date. For converting a string representation like yours you can use the convert. 

Your sample can simple be done with a Convert to Date (Cdate) 

dim theDateIWantToUse = CDate("10/02/2010")

With this date format the program assumes it is has the format like it is the most used in the world. DD MM YYYY

(The DateTime Tick is an Int64 which contains 100th nanoseconds ticks starting at 1-1-1 using the Gregorian Calendar)

---

Success
Cor

Answer 19

lol what a debate out of nothing - almost. If nothing else, its funny to read.

In any case, we have tot much to agree around this thread`s topic, 

Or using Parse, Convert, TryParse, ParseExact or even maybe TryParseExact methods. 

OP just have to try them out all, and see which one suits most to his needs and whishes.

If you ask me, I would still go for ParseExact, IF ONLY the format (Im talking about input formats - in string) is not changing. Else, if there are maybe more possible formats (inputs), then I would go for TryParseExact, and specify all possible formats in the array!

---

Mitja

Answer 20

It is quite good reading. :)

---

You've taught me everything I know but not everything you know.

Answer 21

lol what a debate out of nothing - almost. If nothing else, its funny to read.

Mitja

Mitja, 

You've added this reply to my reply, therefore, is this meant as abuse?

---

Success
Cor

Answer 22

A date is a date, a string is a string. They are different things used for different purposes.

With a date you can do things like finding durations between dates, adding or subtracting time periods, finding the day of the week or the day of the year, converting day or month numbers to names, and so on. It can even be converted to a string (with appropriate consideration for the culture).

A string is an array of Char. It can be reversed, dissected, reassembled and concatenated. It can even be converted to a date (sometimes).

Answer 23

You've added this reply to my reply, therefore, is this meant as abuse?

No Cor,

it just came this way that my post is under yours. Never though of something like that. Its just nice to see and read what kind of "inovations" people can make almost out of nothing. Thats all I wanted to say.

I hope you didnt take any offence. I admire your work, so I would never dare to do something like it.

One more thing: if I want to include someone`s word in my post, I Always quote it.

---

Mitja

Answer 24

it seems you want to modify label text & fetch after correction to the same,

Dim cusDt As Date = Date.ParseExact(lblTodaysDate.Text, _
                                            "dd/MM/yyyy", _
System.Globalization.DateTimeFormatInfo.InvariantInfo)
        
lblTodaysDate.Text = Format$(cusDt, "dd") & _
        "/" & Format$(cusDt, "MM") & "/" & Format$(cusDt, "yyyy")

Same of your thread :

http://social.msdn.microsoft.com/Forums/en-US/vbgeneral/thread/4ea89eb2-bd2b-4fb7-9166-cd3198536110

thanks.

---

Pl. Mark/Proposed as Answer if found your solution Vote as Helpful if related to your topic. Always Motivate others by performing this Action.

Answer 25

Form with a button and a multiline textbox - Imports System.Globalization at the very top

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim date_info As DateTimeFormatInfo = CultureInfo.CurrentCulture.DateTimeFormat()
        TextBox1.AppendText("Short Date Format = " & date_info.ShortDatePattern & vbNewLine)
        TextBox1.AppendText("Short Time Format = " & date_info.ShortTimePattern & vbNewLine)
        TextBox1.AppendText("Date Separator = " & date_info.DateSeparator & vbNewLine)
        TextBox1.AppendText("Full Date&Time Pattern = " & DateTimeFormatInfo.InvariantInfo().FullDateTimePattern & vbNewLine)
        TextBox1.AppendText("Now as Full Date Time = " & Now.ToString(date_info.FullDateTimePattern & vbNewLine))
        TextBox1.AppendText("Now as Short Date = " & Now.ToString(date_info.ShortDatePattern & vbNewLine))
        TextBox1.AppendText("Now as Short Time = " & Now.ToString(date_info.ShortTimePattern & vbNewLine))
        TextBox1.AppendText("Now as Invariant Full Date & Time = " & Now.ToString(DateTimeFormatInfo.InvariantInfo().FullDateTimePattern & vbNewLine))
    End Sub

Answer 26

Dear Sid,

till time you have not give a single reply about your issue status,

pls. always be aware for your thread!

---

Pl. Mark/Proposed as Answer if found your solution Vote as Helpful if related to your topic. Always Motivate others by performing this Action.