Convert String to Date Time [duplicate] - vb.net

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Convert string to DateTime in c#
I am trying to convert a string in the format "20110617111051" to date time.
Currently I am using String.SubString() function to extract year, month, day, time to format a standard string and then using Convert.ToDateTime(string). Is there any other simple way to do this?
Dim x as String="20110617110715"
Dim standard as string = x.SubString(0,4) & "-" & x.SubString(4,2) & "-" & x.SubString(6,2) 'and time
Dim dateTime as DateTime = Convert.ToDateTime(standard)

You can use DateTime.ParseExact.
DateTime date = DateTime.ParseExact(x, "yyyyMMddHHmmss", CultureInfo.CurrentCulture);
VB
Dim myDate as DateTime = DateTime.ParseExact(x, "yyyyMMddHHmmss", CultureInfo.CurrentCulture)

Use the DateTime.ParseExact function in conjunction with the exact format of your input string. Example:
C#:
string input = "20110617111051";
string format = "yyyyMMddhhmmss";
DateTime dateTime = DateTime.ParseExact(input, format, CultureInfo.InvariantCulture);
VB:
Dim input As String = "20110617111051"
Dim format As String = "yyyyMMddhhmmss"
Dim dateTime as DateTime = DateTime.ParseExact(input, format, CultureInfo.CurrentCulture)
See this page for more info on custom date and time strings.

Related

VB.net yyyymmdd format needs to parse as date [duplicate]

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?
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)
Nobody mentioned this, but in some cases the other method fails to recognize the datetime...
You can try this instead, which will convert the specified string representation of a date and time to an equivalent date and time value
string iDate = "05/05/2005";
DateTime oDate = Convert.ToDateTime(iDate);
MessageBox.Show(oDate.Day + " " + oDate.Month + " " + oDate.Year );
Try to see if the following code helps you:
Dim iDate As String = "05/05/2005"
Dim oDate As DateTime = Convert.ToDateTime(iDate)
Try converting date like this:
Dim expenddt as Date = Date.ParseExact(edate, "dd/mm/yyyy",
System.Globalization.DateTimeFormatInfo.InvariantInfo);
Hope this helps.
Try to use DateTime.ParseExact method, in which you can specify both of datetime mask and original parsed string.
You can read about it here: MSDN: DateTime.ParseExact

VB Net String to DateTime

from string dataIni = "2015/12/21 18:28", I would like to parse it into same format DateTime. I am using following code,
Dim dataIni = "2015/12/21 18:28"
Dim dataIniParsed As DateTime = DateTime.ParseExact(dataIni, "yyyy/MM/dd HH:mm", System.Globalization.CultureInfo.InvariantCulture)
However, I am getting "21/12/2015 6:28:00 PM". How to get desired format?
Once you have parsed the text into a DateTime you no longer have a "format" as a DateTime is a data type that just represents a time and a date without any particular format. It's not until you do a .ToString() or Console.WriteLine(...), for example, that the DateTime is converted to a string.
Now, by default, .ToString() produces a string format based on your system settings. Yours is clearly producing "21/12/2015 6:28:00 PM". On my system I use an ISO date format, so my .ToString() produces "2015/12/21 18:28:00" for your date.
You can produce custom formats easily though. Try this code:
Dim dataIniFormatted As String = dataIniParsed.ToString("yyyy/MM/dd HH:mm")
This produces the string "2015/12/21 18:28". Note that this is no longer a DateTime - it's a string - and also that dataIniParsed is still a DateTime (with no inherent formatting).
You can use the code below to format your Date variable. You have to format the date to get the desired result.
Dim dataIni As String = "2015/12/21 18:28"
Dim dataIniParsed As DateTime
dataIniParsed = Convert.ToDateTime(dataIni)
MsgBox(dataIniParsed & " - " & dataIniParsed.ToString("yyyy/MM/dd HH:mm") & " - " & dataIniParsed.GetType.ToString)

How CDATE perform its conversion from string to date on VB.NET

I just want to ask how VB.NET perform is conversion of date from string. I am currently designing a database view and convert the date into MMddyyyy format, but I am worried that CDATE it will read it as ddMMyyyy.
I want it to make it shorter and converting the date using CDATE instead of using the traditional M/d/yyyy h:mm:ss tt.
Example:
Dim myDate As Date = CDate(DataTable.Rows(0).Item("DateValue").ToString())
CDate depends on the control panel regional settings and is not recommended - you should use Date.ParseExact instead
Const MyDateFormat As String = "MMddyyyy"
Dim dte As Date = #2/1/2003#
'convert the date to a string
Dim strDate As String = dte.ToString(MyDateFormat)
'convert the string back to a date
Dim dte2 As Date = Date.ParseExact(strDate, MyDateFormat, System.Globalization.CultureInfo.InvariantCulture)
If dte = dte2 Then
MsgBox("They're the same :-) " & strDate)
Else
MsgBox("They're different :-(")
End If
For your code, it would look like:
Dim myDate As Date = Date.ParseExact(DataTable.Rows(0).Item("DateValue").ToString(), "MMddyyyy", System.Globalization.CultureInfo.InvariantCulture)

VB.NET String Data Manipulation for DateTimePicker

I want to manipulate my String data for example I have a x="20140118"
to y="01/18/2014" how can I do it? I need it for the value in DateTimePicker on VB.NET.
Thanks
DateTimePicker.Value wants a DateTime not a string. So you need to parse it:
Dim dt As DateTime = DateTime.ParseExact("20140118", "yyyyMMdd", CultureInfo.InvariantCulture)
dateTimePicker1.Value = dt
DateTime.ParseExact
Custom Date and Time Format Strings
However, just for the sake of completeness, if you need a string 01/18/2014 from the DateTime you can use DateTime.ToString:
Dim date As String = dt.ToString("MM/dd/yyyy", CultureInfo.InvariantCulture)
If that is your local date format you could also use these more concise approaches:
)
Dim date As String = dt.ToShortDateString()
)
Dim date As String = dt.ToString("d")

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?
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)
Nobody mentioned this, but in some cases the other method fails to recognize the datetime...
You can try this instead, which will convert the specified string representation of a date and time to an equivalent date and time value
string iDate = "05/05/2005";
DateTime oDate = Convert.ToDateTime(iDate);
MessageBox.Show(oDate.Day + " " + oDate.Month + " " + oDate.Year );
Try to see if the following code helps you:
Dim iDate As String = "05/05/2005"
Dim oDate As DateTime = Convert.ToDateTime(iDate)
Try converting date like this:
Dim expenddt as Date = Date.ParseExact(edate, "dd/mm/yyyy",
System.Globalization.DateTimeFormatInfo.InvariantInfo);
Hope this helps.
Try to use DateTime.ParseExact method, in which you can specify both of datetime mask and original parsed string.
You can read about it here: MSDN: DateTime.ParseExact