I have a series: x-values in datetime format and y-values are just numbers. I need to make the graph start at 0, and increment in hours. So if my series started at 12pm tuesday and went until 5am thursday, 12pm tuesday would be 0 and 5am thursday would be 41. No clue on how to convert this.
The answer I came up with:
dim startDate as integer = DateTime.now
dim startDay as integer = startDate.dayOfYear
dim startHour as integer = startDate.hour
dim startMinute as integer = startDate.minute
dim startSecond as integer = startDate.second
For extra precision I also included milliseconds
dim startMillisecond as integer = startDate.millisecond
When it was time to calculate the time difference in hours:
timeDifference = ((thisDay - startDay) * 24) + (thisHour - startHour) + ((thisMinute - startMinute) / 60) + ((thisSecond - startSecond) / 3600) + ((thisMillisecond - startMillisecond) / 3600000)
thisDay, thisHour, thisMinute, thisSecond, thisMillisecond were all calculated the same way as the start variables.
Related
I need help to getting fist data and final data from the weeek
For the example:
Now we are in 3/16/2016 and is week 11, and i need to get data1 for Monday: 3/14/2016 and the final data2 for Sunday: 3/20/2016
We know what week is it and i need to know data for Monday and data for sunday.
Thanks a lot
You can use the property DayOfWeek:
Dim currentTime = New Date(Now.Year, Now.Month, Now.Day)
Dim startOfWeek = currentTime.AddDays(-currentTime.DayOfWeek)
Dim endOfWeek = startOfWeek.AddDays(7)
Dim result = String.Format("Today: '{0:yyyy-MM-dd}' / Start of week: '{1:yyyy-MM-dd}' / End of week '{2:yyyy-MM-dd}'", currentTime, startOfWeek, endOfWeek)
' result = "Today: '2016-03-16' / Start of week: '2016-03-13' / End of week '2016-03-20'"
(Notice that currentTime is created this way in order to have all hours/minutes/secons/millisecons set to zero)
...so if your only input is the week number, in this case you will easily get to your desired currentTime with this simple transformation:
Dim numberOfWeeks = 11
Dim startOfYear = New Date(Now.Year, 1, 1)
Dim currentTime = startOfYear.AddDays(7 * numberOfWeeks)
If i have a string containing a date formatted like this:
1402-3
which means Year: 2014, Week: 02 and Day number 3 (monday is 1), how can i convert this to a normal date? (in this case the date above is today; 2014-01-08 - wednesday 8 jan 2014)
Edit: I came up with a function like this, can anyone tell if this is gonna fail or maybe have a better and better coded function/solution?
Private Function StrangeFormattedDateToRegularDate(ByVal StrangeDate As String) As Date
Dim Y As String = "20" & StrangeDate.Substring(0, 2) 'I'll be dead before this fails, haters gonna hate
Dim W As String = StrangeDate.Substring(2, 2)
Dim D As String = StrangeDate.Substring(5, 1)
'Get first day of this year
Dim RefDate As Date = New Date(CInt(Y), 1, 1)
'Get the first day of this week (can be the year before)
Dim daysOffSet As Integer = DayOfWeek.Monday - RefDate.DayOfWeek
RefDate = RefDate.AddDays(daysOffSet)
'Add as many days as the weeks is
RefDate = RefDate.AddDays(7 * CInt(W))
'now the date is the last day of this week (plus one day), remove the days that are ahead, and remove that extra day
Dim daysToRemove = ((7 - CInt(D)) * -1) - 1
RefDate = RefDate.AddDays(daysToRemove)
Return RefDate
End Function
This should be what you're looking for :) This looked challenging so I tried it. Tell me if it works for you or not :)
Function GetDate(InputDate As String) As DateTime
Dim FirstDayofYear As Date = CType("1/1/20" & Mid(InputDate, 1, 2), Date)
Dim LastDayofYear As Date = CType("12/31/20" & Mid(InputDate, 1, 2), Date)
Dim target As Date
For x = 0 To DateDiff(DateInterval.Day, FirstDayofYear, LastDayofYear)
Dim dfi = DateTimeFormatInfo.CurrentInfo
Dim calendar = dfi.Calendar
Dim weekOfyear = calendar.GetWeekOfYear(FirstDayofYear.AddDays(x), dfi.CalendarWeekRule, DayOfWeek.Sunday)
If CInt(Mid(InputDate, 3, 2)) = weekOfyear And CInt(Mid(InputDate, InStr(InputDate, "-") + 1)) = FirstDayofYear.AddDays(x).DayOfWeek Then
target = FirstDayofYear.AddDays(x)
GoTo skip
End If
Next x
skip:
Return target
End Function
This works up to Year 2099. We're probably all dead by then.
iam trying to get the Dates (Monday - Sunday) for the current Week.
This is my current Code:
Dim kw As Integer = DatePart(DateInterval.WeekOfYear, Now, , FirstWeekOfYear.FirstFourDays)
If DatePart(DateInterval.Weekday, Now, Microsoft.VisualBasic.FirstDayOfWeek.Sunday) = 6 Then
kw = kw + 1
End If
Dim CurrDateFirstDay As Date = DateAdd(DateInterval.Day, 1, ReturnDateForWeekNumber(kw))
For i = 1 To 7
strCurrDay = FormatDateTime(CurrDateFirstDay, DateFormat.LongDate)
........
My Problem is that my code starts at 16.01.2013 and the last date is Thuesday 22.01.2013 next week. Why is that? Why does he start Wednesday 16.01.2013 and not Monday 14.01.2013? And why do i get returned dates of the next week? What iam doing wrong?
Edit:
ReturnDateForWeekNumber:
Public Shared Function ReturnDateForWeekNumber(ByVal iWeek As Integer) As DateTime
Return DateAdd(DateInterval.WeekOfYear, iWeek - 1, FirstDayOfYear)
End Function
What am I doing wrong?
You should step through your code in the debugger and observe the result, as I did:
Dim kw As Integer = DatePart(DateInterval.WeekOfYear, Now, , FirstWeekOfYear.FirstFourDays)
This returns the current week, which is week 3.
If DatePart(DateInterval.Weekday, Now, Microsoft.VisualBasic.FirstDayOfWeek.Sunday) = 6 Then
kw = kw + 1
End If
This checks if the weekday is the 6th day of the week (friday). We're not friday so If condition is not entered.
Dim CurrDateFirstDay As Date = DateAdd(DateInterval.Day, 1, ReturnDateForWeekNumber(kw))
This adds one day to the result of ReturnDateForWeekNumber, which returns:
Return DateAdd(DateInterval.WeekOfYear, iWeek - 1, FirstDayOfYear)
This adds 2 (week 3 minus 1) weeks to the first day of the year (Jan 1st), a tuesday. Jan 1st + 2 weeks = January 15th.
Now remember that you add one day to ReturnDateForWeekNumber, that's why CurrDateFirstDay has a value of January 16th.
Edit
I think your code is overly complicated and uses a lot of legacy VB6 functions. I would do it this way:
Dim myDate As Date = DateTime.Today
Dim dayDiff As Integer = myDate.DayOfWeek - DayOfWeek.Monday
Dim currentDay As Date = myDate.AddDays(-dayDiff) 'Monday
For i = 1 to 7
Console.WriteLine(currentDay)
'Do something with current day
currentDay = currentDay.AddDays(1)
Next
You might have to do some adjustments for your case but I believe this approach is simpler and less error prone.
Dim dateStartDateOfWeek As Date = GetWeekStartDate(52, 2014)
Dim dateEndDateOfWeek As Date = DateAdd(DateInterval.Day, 7, dateStartDateOfWeek)
Private Function GetWeekStartDate(ByVal weekNumber As Integer, ByVal year As Integer) As Date
Dim startDate As New DateTime(year, 1, 1)
Dim weekDate As DateTime = DateAdd(DateInterval.WeekOfYear, weekNumber - 1, startDate)
Return DateAdd(DateInterval.Day, (-weekDate.DayOfWeek) + 1, weekDate)
End Function
I'm trying to count the days between two dates, excluding Saturdays and Sundays. I've written this code so far
Dim startDay As Integer
Dim endDay As Integer
Dim days As Integer
Dim count As Integer
startDay = dtpStartDate.Value.DayOfWeek
endDay = dtpEndDate.Value.DayOfWeek
For days = startDay To endDay
If days = 0 Or days = 6 Then 'Sunday = 0, Saturday = 6
count += 1
End If
Next
lblNoOfDays.Text = count
It works fine if you choose the two dates within the same week. (ex: 23rd Jan to 27th Jan, gives the result 5)
But if I set them to dates in different weeks, (ex : 23rd Jan to 30th Jan, gives the result 1), it gives incorrect results.
I know it happens because of the loop but I can't think of a way to overcome this. Can anyone give me a suggestion, solution??
Thank you
Dim count = 0
Dim totalDays = (dtpEndDate - dtpStartDate).Days
For i = 0 To totalDays
Dim weekday As DayOfWeek = startDate.AddDays(i).DayOfWeek
If weekday <> DayOfWeek.Saturday AndAlso weekday <> DayOfWeek.Sunday Then
count += 1
End If
Next
lblNoOfDays.Text = count
This function calculates the non-weekend days between two dates:
Public Shared Function WorkingDaysElapsed(ByVal pFromDate As Date, ByVal pToDate As Date) As Integer
Dim _elapsedDays As Integer = 0
Dim _weekendDays As DayOfWeek() = {DayOfWeek.Saturday, DayOfWeek.Sunday}
For i = 0 To (pToDate - pFromDate).Days
If Not _weekendDays.Contains(pFromDate.AddDays(i).DayOfWeek) Then _elapsedDays += 1
Next
Return _elapsedDays
End Function
I need to find a way to find the date (DD/MM/YYYY) of the Monday for any week we're on.
For example, for this week, monday would be 09/11/2009, and if this were next week it'd be 16/11/2009.
I managed to get somewhere in the forms of code, but all I got was 'cannot convert to Integer' errors. I was using Date.Today and AddDays().
Thanks for any help. :)
If Sunday is the first day of week, you can simply do this:
Dim today As Date = Date.Today
Dim dayDiff As Integer = today.DayOfWeek - DayOfWeek.Monday
Dim monday As Date = today.AddDays(-dayDiff)
If Monday is the first day of week:
Dim today As Date = Date.Today
Dim dayIndex As Integer = today.DayOfWeek
If dayIndex < DayOfWeek.Monday Then
dayIndex += 7 'Monday is first day of week, no day of week should have a smaller index
End If
Dim dayDiff As Integer = dayIndex - DayOfWeek.Monday
Dim monday As Date = today.AddDays(-dayDiff)
DateTime.DayOfWeek is an enum that indicates what day a given date is. As Monday is 1, you can find the Monday of the current week using the following code:
Dim monday As DateTime = Today.AddDays((Today.DayOfWeek - DayOfWeek.Monday) * -1)
=Format(DateAdd("d", (-1 * WeekDay(Date.Today()) + 2), Date.Today()), "dd/MM/yyyy")
A simple method should get you what you want:
private static DateTime GetMondayForWeek(DateTime inputDate)
{
int daysFromMonday = inputDate.DayOfWeek - DayOfWeek.Monday;
return inputDate.AddDays(-daysFromMonday);
}
You could also extend it for any day that you want as well:
private static DateTime GetDayForWeek(DateTime inputDate, DayOfWeek inputDay)
{
int daysAway = inputDate.DayOfWeek - inputDay;
return inputDate.AddDays(-daysAway);
}
To call the first example just use something like:
DateTime mondayDate = GetMondayForWeek(new DateTime(2009, 11, 15));
Console.WriteLine(mondayDate);
Another approach if Monday is the first day, is this:
Dim today As Date = Date.Today
Dim dayDiff As Integer = today.DayOfWeek - DayOfWeek.Monday
Dim monday As Date = today.AddDays(-dayDiff)
dayDiff = DayOfWeek.Saturday - today.DayOfWeek + 1
Dim sunday As Date = today.AddDays(dayDiff)
There is a day of week method that you can use
Dim instance As DateTime
Dim value As DayOfWeek
value = instance.DayOfWeek
see: http://msdn.microsoft.com/en-us/library/system.datetime.dayofweek.aspx
I just did this in a project I'm working on --I promise, it's correct. This is a method that returns the nth monday after the given date. If the given date is a monday, it returns the next monday.
Public Function GetSubsequentMonday(ByVal startDate As DateTime, ByVal subsequentWeeks As Integer) As DateTime
Dim dayOfWeek As Integer = CInt(startDate.DayOfWeek)
Dim daysUntilMonday As Integer = (Math.Sign(dayOfWeek) * (7 - dayOfWeek)) + 1
'number of days until the next Monday
Return startDate.AddDays(CDbl((daysUntilMonday + (7 * (subsequentWeeks - 1)))))
End Function
Following on from my comments to Meta-Knight's answer, here is a short function that makes the correction I mention in the comments:
Public Function GetFirstOfLastWeek() As DateTime
Dim today As DateTime, daysSinceMonday As Integer
today = DateTime.Today
daysSinceMonday = today.DayOfWeek - DayOfWeek.Monday
If daysSinceMonday < 0 Then
daysSinceMonday += 7
End If
Return today.AddDays(-daysSinceMonday)
End Function
And if your week starts from Monday then you can use something like this:
DateTime mondayDate = DateTime.Now.AddDays(((DateTime.Now.DayOfWeek == DayOfWeek.Sunday?7: (int)DateTime.Now.DayOfWeek) - 1)*-1);
DateTime sundayDate = DateTime.Now.AddDays(7 - (DateTime.Now.DayOfWeek == DayOfWeek.Sunday?7: (int)DateTime.Now.DayOfWeek ));
Dim dayOfWeek = CInt(DateTime.Today.DayOfWeek)
Dim startOfWeek = DateTime.Today.AddDays(+1 * dayOfWeek).ToShortDateString
Dim endOfWeek = DateTime.Today.AddDays(6 + dayOfWeek).AddSeconds(+1).ToShortDateString
MessageBox.Show(startOfWeek)
MessageBox.Show(endOfWeek)
Example:
If today is 03/09/2020,
startOfWeek will be 07/09/2020 and
endOfWeek will be 13/09/2020.