I need to convert a dd/mm/yy date to dd/mm/yyyy automatically.
Example: if I insert in the textbox "12/01/90", the program should automatically convert the text to "12/01/1990" or "01/01/20" to "01/01/2020".
Also, I should check the date to make sure it is correct.
Example: if I enter "80/70/2000" it must give me an error because the date does not exist. How can I do? Thanks in advance.
If you have the input as a string, you would first parse it into a date with the format specifier, and then convert it back into a string.
Dim input as String = "22/03/19" ' dd/mm/yy
Dim dt as DateTime = DateTime.MinValue
If (DateTime.TryParseExact(input,
"dd/MM/yy",
System.Globalization.CultureInfo.InvariantCulture,
System.Globalization.DateTimeStyles.None,
dt
)) Then
Dim output as String = dt.ToString("dd/MM/yyyy")
Console.WriteLine(output)
else
Console.WriteLine("Error")
end if
Output:
22/03/2019
You can try it here
Related
I have a string with a date in this format. "24-11-2015" or "dd-MM-yyyy". I need to convert this to a date with this format. "2015-11-24" or "yyyy-MM-dd".
I've tried several ways, and all of them rely on my system format for this to work. If i run my program on a computer with english time format this works.
Date.ParseExact("24-11-2015", "dd-MM-yyyy", System.Globalization.DateTimeFormatInfo.InvariantInfo)
But if i run it on a computer running danish format i get error because there is no 24th month. How do i make the date format independent of my system time format.
Solution:
Dim dateTime As String = "24-11-2015"
Dim dt As DateTime = Convert.ToDateTime(dateTime)
Console.WriteLine("{0}-{1}-{2}", dt.Year, dt.Month.ToString("D2"), dt.Day.ToString("D2"))
Solution 2:
Dim dateTime As String = "24-11-2015"
Dim dt As DateTime = Convert.ToDateTime(dateTime)
Dim format As String = "yyyy-MM-dd"
Dim str As String = dt.ToString(format)
Console.WriteLine(str)
You can also try Formatting Date and Time for a Specific Culture.
I'm taking date from my csv file
Dim odateq As String = sData(0).Trim()
I am getting odateq as 9/15/2015
I want to convert this to 15/9/2015. So I wrote code like this
Dim newdate As DateTime = DateTime.ParseExact(odateq, "dd/MM/yyyy", System.Globalization.CultureInfo.CurrentCulture)
And I'm getting an error like this :
String was not recognized as a valid DateTime.
any help is very appreciable...thanks
the code you wrote is using the wrong format; the date you have is in the format M/d/yyyy (month and day without leading zero are a guess because you did not specify it).
try with this one:
Dim newdate As DateTime = DateTime.ParseExact(odateq, "M/d/yyyy", System.Globalization.CultureInfo.CurrentCulture)
the format you set in the ParseExact was telling the function to expect a date in the format dd/MM/yyyy like 01/05/2015 but what you have is not in that format.
after you parse the input date, to get a string with format dd/MM/yyyy use:
Dim dateAsText As String = newdate.ToString("dd/MM/yyyy")
I have user input that needs to be verified that the string is in the datetime format as follows:
yyyy-MM-dd HH:mm:ss
The user does not have a choice for any other format but for error checking how do I detect whether string in is this format.
sDate = DateTime.ParseExact(startDate, "yyyy-MM-dd HH:mm:ss", CultureInfo.CurrentCulture)
startdate is the string.
This code will help you to convert the date into the format which which you wanted to check
Dim format As String = "yyy-MM-dd HH:mm:ss" 'let input be "02-02-2014 12:12:12"
MsgBox(dt.ToString(format)) ' the output will be 2014-02-02 12:12:12
it works properly in VS 2010(windows 7)
IMHO, you should consider using DateTimePicker control for taking date/time input. Use Custom Format (if needed). It will save you to first take it and validate it.
You should use DateTime.TryParseExact if you want the date/time format to be exactly in a particular format.
Function IsValidDate(ByVal dateValue As String) As Boolean
Return DateTime.TryParseExact(dateValue, "yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture, DateTimeStyles.None, Nothing)
End Function
I can't get my date to format as yyyy-MM-dd, for instance 2013-01/15. I have tried both custom and predefined Date/Time formats. Any of these should work:
Dim myDate As Date = "01/15/2013"
myDate = myDate.ToString("o")
myDate = myDate.ToString("yyyy-MM-dd")
Format(myDate, "yyyy-MM-dd")
But they all keep myDate as "01/15/2013". What am I doing wrong?
A Date value doesn't have any format at all. When you format the date into a string and assign it back to the variable, it's parsed to a Date value again, and loses the formatting.
To keep the date in the formatted string form, you need to keep it as a string:
Dim formatted As String = myDate.ToString("yyyy-MM-dd")
I need to get a date field from MM/dd/yyyy to yyyy/MM/dd in vb.net but it should still be a date field afterward so that I can match it against a date in a database.
At the moment all I'm managing to do is to change it to a string in that format.
I tried this type of code which also did not work.
DateTime.Parse(yourDataAsAString).ToString("yyyy-MM-dd")
fromDeString = String.Format("{0:yyyy/MM/dd}", aDate)
fromDate = Format("{0:yyyy/MM/dd}", aDate)
Any help would be much apreciated, thanks
You're not understanding that a date object does not store the digits in any particular format. The only way to get the digits formatted in the order you want is to convert it to a string. Why do you need to compare them in a particular format? A date is a date no matter how it is formatted. 12/15/78 == 1978/12/15.
If you are not able to compare dates from the DB against a date object in VB, it is likely that the date you are comparing to in the database is being returned to you in string format, in which case you should covert it to a date object for comparison.
Dim sDate As String = "2009/12/15" 'Get the date from the database and store it as a string
Dim dDate As New Date(2009, 12, 15) 'Your date object, set to whatever date you want to compare against
Select Case Date.Compare(dDate, Date.Parse(sDate))
Case 0
'The dates are equal
Case Is > 0
'The date in the database is less
Case Is < 0
'The date in the database is greater
End Select
Here's a sample module demonstrating the functionality you desire.
Imports System.Globalization
Module Module1
Sub Main()
Dim culture As New CultureInfo("en-us", True)
Dim mmDDyy As String = "10/23/2009"
Dim realDate As Date = Date.ParseExact(mmDDyy, "mm/dd/yyyy", culture)
Dim yyMMdd As String = realDate.ToString("yyyy/MM/dd")
End Sub
End Module
Hope this helps.
Kind Regards
Noel
Your second should actually work. Instead just try:
dim chislo as date = date.now dim message As String = $"
Today`s Date: {String.Format("{0:dddd, dd/MM/yyyy}", Chislo)} "
MsgBox(message)