How to calculate the last day of the next month using vb.net?
try yo use DaysInMonth Function which returns the number of days in the required month.
Example
System.DateTime.DaysInMonth(2016,May)
This will return (31), so you can get the date format in addition to this number to get last day of this month.
An other way is to get the first day of the month after and substract 1 day.
Dim d As DateTime
d = DateTime.Now.AddMonths(2)
d = New DateTime(d.Year, d.Month, 1).AddDays(-1)
If you after the actual date....
You could use DateSerial(Year, Month, 0) this will return the last day of the month prior to the month entered.
Entering DateSerial(2016, 07, 0) will return "30/06/2016"
To get the last day of next month do DateSerial(Now.Year, Now.Month + 2, 0)
This works fine for February and also the year end as well (DateSerial(2016, 3, 0) returns "29/02/2016", DateSerial(2016, 11 + 2, 0) returns "31/12/2016")
Dim N = DateTime.Now.AddMonths(1)
Dim D = New DateTime(N.Year, N.Month, DateTime.DaysInMonth(N.Year, N.Month))
D will have the last day of next month.
Related
I have a table with week number and day of week.
Example:
J2 = 18
G2 = Monday
How can I convert this to 2018-04-30?
I can find lots of threads for converting the other way around, meaning date to week. But I can't find anything on week + weekday to date.
Anyone know of a method?
The (optional) second argument of the WEEKDAY function determines what the first day of the week is. The two most common choices are:
1: Sunday (1) to Saturday (7)
or
2: Monday (1) to Sunday (7)
But, you can start on Wednesday, Friday, etc if you want. Pick an option now.
So, start with 1st January (of whichever unspecified year you're working with), and subtract the weekday of 1st January, according to whichever start-day you picked. This gives you a baseline for Week 1. To get to the start of Week n, you just need to add 7*(n-1) days.
Finally, you need to add the weekday back on. I'm going to recommend using MATCH on an array. Your array will be your weekdays, in order, surrounded by curly brackets. So, for Sunday-to-Saturday, you would use
MATCH(G2,{"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"},0)
to get a number from 1 ("Sunday") to 7 ("Saturday"), or #NA if cell G2 does not contain a day-name.
Stick it all together, and you get something like this:
=DATE(YEAR(NOW()),1,1) - WEEKDAY(DATE(YEAR(NOW()),1,1),1) + 7*(J2-1) + MATCH(G2,{"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"},0)
Try this, necessary comments in code:
Option Explicit
Sub GetDate()
Dim year As Date, day As Long
'convert day in G2 to integer
Select Case Range("G2").Value
Case "Monday"
day = 1
Case "Tuesday"
day = 2
'rest of cases
End Select
'declare what year you want
year = "01-01-2018"
'move from first week to the week specified in J2
year = DateAdd("d", (Range("J2").Value - 1) * 7, year)
'move back to first day of the week
Do While DatePart("w", year, vbMonday) <> 1
year = DateAdd("w", -1, year)
Loop
'find date of particular day
Do While DatePart("w", year, vbMonday) <> day
year = DateAdd("w", 1, year)
Loop
End Sub
The determination depends critically on your definition of "week number".
If you are using the ISO-8601 definition, where a Week starts on Monday and week 1 contains the first Thursday of the year, you can use this worksheet formula:
=DATE(YEAR(TODAY()),1,-2)-WEEKDAY(DATE(YEAR(TODAY()),1,7),14)+$J$2*7+MATCH($G$2&"*",{"Monday";"Tuesday";"Wednesday";"Thursday";"Friday";"Saturday";"Sunday"},0)-1
you may need to change the commas to semicolons depending on your regional settings
To explain:
First, find the last Monday of the previous year:
DATE(YEAR(TODAY()),1,-2)-WEEKDAY(DATE(YEAR(TODAY()),1,7),14)
Then add seven(7) times the number of desired weeks:
+$J$2*7
Then add the number of days from Monday to the desired day for that week:
+MATCH($G$2&"*",{"Monday";"Tuesday";"Wednesday";"Thursday";"Friday";"Saturday";"Sunday"},0)-1
Following code gives last day of the previous month.
MonthCalendar1.SelectionEnd = MonthCalendar1.SelectionStart.AddDays(-MonthCalendar1.SelectionStart.Day)
Which code gives first day of MonthCalendar1 selected year?
So if selected date is for example 13.06.2015 how to get 01.01.2015?
Just create a new Date using only the year of the reference date like This:
Dim firstOfYearDate As Date = New Date(baseDate.Year, 1, 1)
Like This
MonthCalendar1.MaxSelectionCount = 365
MonthCalendar1.SelectionEnd = New Date(2015, 06, 13)
MonthCalendar1.SelectionStart = New Date(MonthCalendar1.SelectionEnd.Year, 1, 1)
If you want to go with your current method of adding negative days, simply subtract one from DateTime.DayOfYear:
MonthCalendar1.SelectionEnd = MonthCalendar1.SelectionStart.AddDays(-(MonthCalendar1.SelectionStart.DayOfYear-1))
If you want the last day of the selected year, use DateTime.DaysInMonth():
Dim dt As New DateTime(MonthCalendar1.SelectionStart.Year, 12, DateTime.DaysInMonth(MonthCalendar1.SelectionStart.Year, 12))
I am writing a code to ensure that the data date of a system is not later than 2 business month-end date. For instance, if the job run date for the system is 23/12/2015, the valid data date is 30/10/2015 and 30/11/2015. The dates involved are only business days.
I have this code below:
If DateDiff("m", dataDate, jobRunDate) > 2 Then
MsgBox "Error in dataDate"
End If
However, I do not know how to find:
The last day of the month
Compute 2 business month back
Any help will be greatly appreciated. Thanks!
To find the last day of the month, you can find the first day of the next month and subtract a day:
Dim last As Date
Dim current As Date
current = Now
last = DateSerial(Year(current), Month(current), 1) - 1
Debug.Print last
To get the last business day of a month, just subtract days until it falls on a weekday:
Do While Weekday(last, vbMonday) > 5
last = last - 1
Loop
Debug.Print last
Combining the 2 ideas and extracting it as a function gets you this:
Private Sub Example()
Debug.Print LastBizDayOfMonth(Year(Now), Month(Now) - 1)
Debug.Print LastBizDayOfMonth(Year(Now), Month(Now) - 2)
End Sub
Private Function LastBizDayOfMonth(inYear As Integer, inMonth As Integer) As Date
LastBizDayOfMonth = DateSerial(inYear, inMonth + 1, 1) - 1
Do While Weekday(LastBizDayOfMonth, vbMonday) > 5
LastBizDayOfMonth = LastBizDayOfMonth - 1
Loop
End Function
Here is how to get the last day of a month:
Sub LastDayOfMonth()
Dim d As Date
mnth = 12
yr = 2015
d = DateSerial(yr, mnth + 1, 0)
MsgBox d
End Sub
You must then subtract two months from that date. If the result falls on a Saturday or Sunday, you must decide if you want to go forward to the next Monday or backward to the previous Friday.
I want to set a specific date (October 06 , 2014) to be the 1st Week of the year. So when I use the =weeknum() formulaR1C1 it will return the week number.
I'm currently working on a worksheet that gets updated daily so the week number will be updated every week only. In column ("D") indicates the week number. and column ("B") indicates the daily date.
If i use the =weeknum() formula on it returns the value of 41, but it needs to be week number 1.
How about creating your personalized function?
It just consists of counting how many days there are between the date you insert (myDate) and the date which is considered to be the first day of the year (first_day), dividing this number by 7, taking its integer and adding up 1. It will always give you the right one.
Public Function special_weeknum(ByVal myDate As Date) As Integer
Dim first_day As Date: first_day = #10/6/2014#
Dim myWeek As Integer: myWeek = Int((myDate - first_day) / 7) + 1
special_weeknum = myWeek
End Function
Please note that this approach would allow you also to pass the first day as a user input:
Public Function special_weeknum(ByVal myDate As Date, ByVal first_day As Date)
Dim myWeek As Integer: myWeek = Int((myDate - first_day) / 7) + 1
special_weeknum = myWeek
End Function
so that you will always be able to decide which is the day you must consider as first day of the year.
My user will typically enter some trip info including a day and month but typically they just enter the day. For example they would enter "TRIP1500/31" where the 31 is implied that its in JULY. The trip date can be at most 7 days in the past or 7 days in the future. So now what Im trying to do is guess what month that day is meant to be. So far I have:
Dim diff As Integer = CInt(tripDay) - Date.Now.Day
Select Case diff
Case 0
'same day so its probably current month
End Select
What I'm having trouble with is the other cases where the current day and the trip day overlap month-to-month. If the current day and trip day are in current month then the most difference they can be is +/-7 days but what about the other cases? Any help appreciated.
Function GetTripDate(day As Integer) As Date
Dim today As Date = Date.Today
For i As Integer = -7 To 7
Dim dt As Date = today.AddDays(i)
If dt.Day = day Then Return dt
Next
Throw New ArgumentOutOfRangeException("Invalid trip day.")
End Function
This gives you the date(incl. month) of the nearest date with the given day:
Dim maxDiffDays = 7
Dim tripDay = 31
Dim today = Date.Today
Dim tripDate = New Date(today.Year, today.Month, tripDay)
Dim tripDates = {tripDate.AddMonths(-1), tripDate, tripDate.AddMonths(1)}
Array.Sort(Of Date)(tripDates, Function(d1, d2) ((today - d1).Duration).CompareTo((today - d2).Duration))
Dim nearestDate = tripDates.First()
If ((today - nearestDate).Days <= maxDiffDays) Then
Console.WriteLine("Nearest month for trip date is: " & nearestDate.Month)
End If
It creates a Date from a given day, then it creates the two surrounding dates one month after and previous this date. This array will be sorted from the positive timespan from today(TimeSpan.Duration). So the firs't date in the array is the nearest date with the correct month.