It seems like I keep having problems with dates. I am using the following code:
Dim LocalDateCultureProvider As New CultureInfo(CultureInfo.CurrentCulture.ToString)
Dim CurrentDate As DateTime = Convert.ToDateTime(System.DateTime.Now.ToString("dd/MM/yyyy"), System.Globalization.CultureInfo.InvariantCulture)
ExpiryDate = DateTime.ParseExact(strDate, "dd/MM/yyyy", LocalDateCultureProvider)
If DateTime.Compare(ExpiryDate, CurrentDate) < 0 Then
MsgBox("This file has expired.")
Exit Sub
End If
Here I am reading strDate as a string and for one example, the value of this is "29/09/2012" However, in the ExpiryDate line it converts to #09/29/2012# so that in the comparison with today's date which is stored (correctly in my opinion) in CurrentDate as #10/6/2012# I get the If condition to be true (wrongly).
BTW, I also tried
Dim LocalDateCultureProvider As New CultureInfo(System.Globalization.CultureInfo.InvariantCulture.ToString)
just to see if that was causing the problem. I am trying to build something that will work in all Cultures. No matter what the local settings are, I want to test for expiration by comparing the current system date with an expiration date which I receive as a string. Please tell me how to go about this so I can get consistent results.
TIA,
Chiwda
No, you parse the CurrentDate incorrectly. CultureInfo.InvariantCulture expects the month before the day but you formatted it with the day first. You are writing unnecessary code, simply fix with:
If DateTime.Compare(ExpiryDate, DateTime.Now) < 0 Then
Related
I have a problem on VB.Net which a part of my system has a error. It doesn't save the date thus generating this error. The format was identical to the output on the datetime Picker.
ElseIf Date.Parse(expirationDTP.Value.ToString("MM/dd/yyyy")) <= Date.Parse(Date.Now.ToString("MM/dd/yyyy")) Then
MsgBox("Select the expiration date of the stock!")
This is an image of the output.
Date Output
Thanks!
expirationDTP.Value and Date.Now already are of type Date. Why are you converting them into strings only to convert them back to Date objects?
Just compare them directly:
ElseIf expirationDTP.Value <= Date.Now Then
For future reference, the actual error occurs because Date.Parse() tries to use the current system's cultural settings to parse the date. If you need to parse a specific date format you should use Date.ParseExact():
Date.ParseExact("01/20/2018", "MM/dd/yyyy", CultureInfo.InvariantCulture)
EDIT:
Try comparing the Date properties of the two Date objects:
ElseIf expirationDTP.Value.Date <= Date.Now.Date Then
If it still doesn't work you're going to have to check if it's any preceding ElseIf or the initial If that gets executed instead. As you haven't shown any more code than that there's not much more I can do.
Hye guys.. need some help from you.. sorry for my broken english.
actually, what im doin is, i need to upload some data from csv file into Microsoft Access which is contain a LASTDATE date.. for coding overall okay. but i getting problem with date.. when i upload into database, i have to insert follow by LASTDATE date in csv file..but what i get is, in database, it refer to current time on laptop.
for example, LASTUPDATE is 16/10/2017.. when i upload, LASTDATE will follow by current time on my laptop..
here is a code..
Public Function GetDateFormatToDB(vDateTime As String) As String
Try
Dim format As String = "MM/dd/yyyy HH:mm:ss"
Dim expenddt As Date
Date.TryParseExact(vDateTime, format, System.Globalization.DateTimeFormatInfo.InvariantInfo, Globalization.DateTimeStyles.None, expenddt)
Return expenddt
Catch ex As Exception
Return Nothing
End Try
End Function
If you need to return Nothing in case of an error your function should have Nullable(Of Date) (or Date?) as return value.
If you only want to store the date-part of a Date object, use the Date property of your Date object.
In your code snippet it would be expenddt.Date. This way you get rid of the time-part of the Date object.
DateTime.FromOADate(Double.Parse(myValue)).ToShortDateString()
this will help
I am working on vb.net application
am getting date like this :
recevdate = rs("ITIReceiveddate")
my recevdate format is like this : 2/27/2016 month/date/year
i want to convert like this : date.month.year 27.2.2016
so i wrote code like this :
Dim dt as string = DateTime.ParseExact(recevdate, "dd.MM.yyyy", Nothing)
but its getting error ..
What is wrong with my code? how i can rectify this issue?
any help is very appreciable..Thanks
DateTime.ParseExact returns a DateTime, not a string. Your project is setup with the Option Strict set to Off and this enables this kind of automatic conversions. But it is, as usual, a trap waiting to kick on unsuspecting programmers.
To execute correctly you need
Dim recevdate = "2/27/2016"
Dim dt As DateTIme = DateTime.ParseExact(recevdate, "M/d/yyyy", Nothing)
Dim formattedString = dt.ToString("d.M.yyyy")
Console.WriteLine(formattedString)
Notice that you have an error also in your formatted mask for parsing the date. If your date has only one digit for months or one digit for days then you need just one M and one d both on the parsing and in the formatting back to string
I am experiencing a problem when attempting to read a date from an excel sheet. (The date column is formatted the same as the short date format of the computer its opened on). I populate the dates from the excel sheet into a datagrid with success, but when I attempt to parse the date (To format it appropriately), I get a error saying the string wasn't a valid DateTime value. The computer's short date format is dd/MM/yyyy. This is the code I use to try parsing the date. The following code is an example of where the process fails.
Dim dateParsed AS DateTime = DateTime.Parse("14/01/2013").ToString("yyyy-MM-dd")
Is there some way to programatically get the system's short date format and use ParseExact instead or any suggestions?
You want to parse exact, using the current cultures short-date format?
Dim dt As DateTime = DateTime.ParseExact(str, "d", CultureInfo.CurrentCulture)
Additionally, if you actually need to see the ShortDate format for yourself get it through the CurrentCulture.
CultureInfo.CurrentCulture.DateTimeFormat.ShortDatePattern
You can try this piece of coding
Dim dt As DateTime = DateTime.Parse("1/14/2013").ToString
Dim f As String = Format(dt, "yyyy-MM-dd")
I seem to have a date formatting problem every day!
I am querying a table and am getting a date back in the format dd/mm/yyyy (as a string btw). Brilliant! thats what I want. But, now I want to convert that string to a date so i can do
dim dayNumber as integer = day.DayOfWeek
But when I convert it to a date it changes it to #m/dd/yyyy#. AHHHH! how can I change this?
here is my code i've tried
Dim ActivityDate As String
If dt.Rows(i)("Date") Is DBNull.Value Then
ActivityDate = ""
Else
ActivityDate = dt.Rows(i)("Date")
End If
Dim ci As New System.Globalization.CultureInfo("en-CA")
Dim theDate As Date = Date.Parse(ActivityDate, ci)
Dim day As Integer = theDate.DayOfWeek
Cheers
Brilliant! thats what I want
That's not what you want. It is the worst possible format for a date because it is so horribly ambiguous. Date string formats depend on the current culture. "4/1/2010" is Unicorn day at SO, it is day in January in Europe. "#4/1/2010#" is a legacy VB6 format.
Always store dates in a DateTime in your code. Always store dates in a database column type of datetime in your dbase. There is never any ambiguity and you'll have an easy time with the DateTime members to manipulate dates.
If you convert the string to a date, you can always output it back to the original format using a custom format string: http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx
The correct solution here (at least until you tell us why this isn't possible) is to update your database to use a datetime column type rather than a varchar. Now we also know that this column has no NULL values, because otherwise you'd be complaining about exceptions on your Date.Parse() call. After applying both those sentences, you can trim all that code down to a simple one-liner:
Dim day As Integer = DirectCast(dt.Rows(i)("Date"), DateTime).DayOfWeek
May I also ask why you're looping through the table row by row? I've worked in a shop where that was the norm, but since I've left there I've run in to alternatives and more and more I'm coming to find looping through a datatable as just wrong. It's an older imperative coding style, and generally you want to go for a declarative coding style.
Are you parsing it like this:
Dim newDate as DateTime = DateTime.Parse(myDate)
If the culture of your system does not use that date format, then you should get that date string as an actual date:
' canadian date format is dd/mm/yyyy
Dim ci As New System.Globalization.CultureInfo("en-CA")
Dim theDate As Date = Date.Parse("13/04/2010", ci)
Make sure you specify an exact parse format like so:
Console.WriteLine(DateTime.ParseExact("17/12/2010", "dd/mm/yyyy", null));
I am not sure what the last parameter is but it is safe to ignore it.
I'm guessing that you are seeing the #m/dd/yyyy# in the debugger, like this screenshot below. Don't worry!
A Date variable isn't stored as a string. The debugger has to convert your Date into a string to display it, and it insists on showing dates in #m/dd/yyyy# format. But that doesn't have any effect on the runtime behaviour of your program.
Screenshot of Visual Studio Debugger http://img707.imageshack.us/img707/6205/debugger.gif