i need to store all the days between two dates in an ARRAY.
for eg:
from_date is: 2014-09-20, to_date : 2014-09-24
the result will be
2014-09-20, 2014-09-21, 2014-09-22, 2014-09-23, 2014-09-24.
Any help will be appreciated..
One way: LINQ
Dim days = From day In Enumerable.Range(0, (toDate - fromDate).Days + 1)
Select fromDate.AddDays(day)
Dim result As Date() = days.ToArray()
The classic way without math which also works in .NET 2:
Dim dayList As New List(Of Date)
Dim currentDate = fromDate
While currentDate <= toDate
dayList.Add(currentDate)
currentDate = currentDate.AddDays(1)
End While
Dim result As Date() = dayList.ToArray()
If you need a string() as commented just append ToString(). For example:
Dim days = From day In Enumerable.Range(0, (toDate - fromDate).Days + 1)
Select fromDate.AddDays(day).ToString()
Dim result As String() = days.ToArray()
Related
Good day. There is the following code that subtracts from one date another:
Dim dt As New DateTime(2021, 8, 19)
Dim dt2 As New DateTime(2022, 8, 29)
MsgBox("Days Remaining : " & (dt2 - dt).Days)
tell me how to subtract format dates:
19.08.2021 14:07:16 - 24.08.2021 08:24:01
throwing away the time. I'm only interested in how to subtract dates of this format.
Date and time are entered in text boxes
You would get the Date property (documentation) of the DateTime values. Also, I would probably recommend using DateTime.Subtract (documentation) which would return a TimeSpan value.
Take a look at this example:
Dim dt = New DateTime(2021, 8, 19)
Dim dt2 = New DateTime(2022, 8, 29)
Dim daysLeft = dt2.Subtract(dt).Days
Example: https://dotnetfiddle.net/LMuWtu
You have to parse the formatted Dates then use .Date to keep only the Date part and throw away the time. Then you can substract and use TotalDays:
Dim input1 As String = "19.08.2021 14:07:16"
Dim input2 As String = "19.08.2021 14:07:16"
Dim d1 As DateTime = DateTime.Parse(input1).Date
Dim d2 As DateTime = DateTime.Parse(input1).Date
Dim days As Single = (d1 - d2).TotalDays
The formatted dates should match your Culture format. You can also use Parse overload to use another Culture : https://learn.microsoft.com/fr-fr/dotnet/api/system.datetime.parse?view=net-5.0#System_DateTime_Parse_System_String_System_IFormatProvider_
If I have two dates
Dim date1 As String = 01/05
Dim date2 As String = 01/07
Dim date As Integer
Date = 2
How do I go about making sure that 2 handles month changes and just general dates in this format?
You would parse the strings into DateTime values, then you can subtract them to get a TimeSpan value that is the difference. Use the Days property to get the whole days from the value:
Dim date1 As String = "01/05"
Dim date2 As String = "01/07"
Dim d1 = DateTime.ParseExact(date1, "MM'/'dd", CultureInfo.InvariantCulture)
Dim d2 = DateTime.ParseExact(date2, "MM'/'dd", CultureInfo.InvariantCulture)
Dim date As Integer = (d2 - d1).Days
How would I make my application do an event when there is a certain date? I can't seem to find something that works. Year doesn't matter, just day and month is all I need.
Since day and month is all you want to match on:
Dim myDate As Date = Date.Now
Dim someMonth As Integer = 4
Dim someDay As Integer = 13
If myDate.Month = someMonth AndAlso myDate.Day = someDay Then
... month and day are matched
End If
Use IsDate....
If IsDate(MyDate) Then.....
Update various ways of defining date
'DateTime constructor: parameters year, month, day, hour, min, sec
Dim MyDate1 As New Date(2012, 12, 10, 12, 0, 0)
'initializes a new DateTime value
Dim MyDate2 As Date = #12/10/2012 12:00:52 AM#
'using properties
Dim MyDate3 As Date = Date.Now
Dim MyDate4 As Date = Date.UtcNow
Dim MyDate5 As Date = Date.Today
Try something like this:
Dim thisDate As Date = New Date(2014, 4, 13) ' Assuming this is provided
Dim certainDate As Date = New Date(2013, 4, 13) ' Assuming this is provided
If thisDate = New Date(thisDate.Date.Year, certainDate.Month, certainDate.Day) Then
Debug.Print("dates equal excluding year")
Else
Debug.Print("dates UNequal excluding year")
End If
Rememebr, this will always create a new date object for comparison but it works.
Hope it helps!
i try loop while with datetime each on weekly in VB.NET 2008.
This Code
Private Sub Button1_Click()....
'Select DateTime
Dim strDate As Date = dateTimePicker.Value.ToString("yyyy-MM-dd")
'one week (+7)
Dim strDateWeek As String = DateAdd("d", +7, dateTimePicker.Value.ToString("yyyy-MM-dd"))
'DateCurrent
Dim strDateNow As String = DateAdd("d", 0, Now.ToLongDateString())
'While strDate < strDateNow
'ListBox1.Items.Add(strDateWeek)
'End While
ListBox1.Items.Add(strDateWeek)
End Sub
Example
I select on datetimepicker at "04/02/2013"
Output now: 11/02/2013
But I need Output each on weekly
11/02/2013
18/02/2013
25/02/2013 >>> To Current Week
I try loop While, But don't work.
Thanks you for your time. :)
You could do a while loop until the datetime is greater than today?
You want to use DateTime rather than Date, so you can compare to a DateTime.Now
You want to set your actual DatePicker value to a variable, else it will always be the same and you will just get an infinite loop.
Dim datePickerValue As DateTime = DateTimePicker.Value
Dim strDate As Date = DateTimePicker.Value.ToString("yyyy-MM-dd")
Dim strDateWeek As String
Dim strDateNow As String = DateAdd("d", 0, Now.ToLongDateString())
While datePickerValue < DateTime.Now()
strDateWeek = DateAdd("d", +7, datePickerValue.ToString("yyyy-MM-dd"))
datePickerValue = DateAdd("d", +7, datePickerValue.ToString("yyyy-MM-dd"))
ListBox1.Items.Add(strDateWeek)
End While
Just done it on my VS using your naming conventions and this works fine for me
It's been a long time since I didn't have used VB, but maybe I can help?
In your code, using while could be a wrong choice perhaps you could use a for with a break instead.
for I = 1 to 10
Dim strDateWeek As String = DateAdd("d", +7 * i, dateTimePicker.Value.ToString("yyyy-MM-dd"))
.
.
.
or
while(...)
I += 1
Dim strDateWeek As String = DateAdd("d", +7 * i, dateTimePicker.Value.ToString("yyyy-MM-dd"))
Hope that helps.
Try this:
Dim dtAux As Date = dateTimePicker.Value
Dim dtEnd As Date = Date.Today.AddDays(7 - dt.DayOfWeek)
While dtAux <= dtEnd
ListBox1.Items.Add(dtAux.ToString("yyyy-MM-dd"))
dtAux = dtAux.AddDays(7)
End While
The date dtEnd is the last day of the current week, if you want the loop to stop on the current date simply change the while condition to:
While dtAux <= Date.Today
Would anyone know how to convert any date first into a Saturday and then into yyww (weekyear) in VB.NET?
And vice versa, ie yyww into a Saturday?
Dim d As DateTime = #1/20/2009#
d = d.AddDays(DayOfWeek.Saturday - d.DayOfWeek)
Dim myCal As New System.Globalization.GregorianCalendar
Dim wkOFyr As Integer = myCal.GetWeekOfYear(d, _
Globalization.CalendarWeekRule.FirstDay, _
DayOfWeek.Sunday)
Dim s As String
s = d.ToString("yy") & wkOFyr.ToString.PadLeft(2, "0"c)
Assuming your weeks start on Sunday, you could probably do something like this to get the saturday of the current week:
Dim daysToAdd As Integer = DayOfWeek.Saturday - yourDate.DayOfWeek
Dim dateSaturday as Date = yourDate.AddDays(daysToAdd)
I didn't test it though.
Then you could get the weekyear by doing something like:
Dim weekYear As Integer = CInt(Math.Ceiling(dateSaturday.DayOfYear / 7))
Using the reverse logic you can find the saturday corresponding to the weekyear.