What function will let us know whether a date in VBA is in DST or not?
For non-current dates (DST 2007+):
First, you need a function to find the number of specific weekdays in a month:
Public Function NDow(Y As Integer, M As Integer, _
N As Integer, DOW As Integer) As Date
' Returns Date of Nth Day of the Week in Month
NDow = DateSerial(Y, M, (8 - Weekday(DateSerial(Y, M, 1), _
(DOW + 1) Mod 8)) + ((N - 1) * 7))
End Function
Then, you can check for the DST day versus the following function calls:
Fall: NDow(Year(newdate), 11, 1, 1)
Spring: NDow(Year(newdate), 3, 2, 1)
For the current date:
Call the Windows API function GetTimeZoneInformation,
and it will return an enum (integer) with the status.
I got the code for this from Chip Pearson's great Excel site.
Pearson's site
For anyone wondering how to account for daylight saving time in Europe (central europe time), I modified the script from Chip Pearson. The last sunday of March (2 AM to 3 AM) and October (3 AM to 2 AM) are the days when the hour switching occurs.
Following code is the click event of a button in Excel:
Dim dates As String
dates = "A1:A20"
For Each c In Worksheets("Sheet1").Range(dates).Cells
If (IsDateWithinDST(c.Value)) Then
c.Value = DateAdd("h", 1, c.Value)
End If
Next
The module containing the necessary methods are to be found here.
More info on DST in Europe.
Related
We can find different approaches to determining the week of the month, and even though there are many pages on 1:4 and/or 1:5, there is very few around 1:6 approach.
So to give you a bit of the context, I am working with a pivot table in Excel which gets its values from a Power Query source.
In Power Query, there is a function Date.WeekOfMonth which takes in the date and returns a number between 1 and 6.
In this definition, weeks start from Sunday and ends on Saturday.
So, for example, the first two days of October 2021 -i.e. Fri & Sat- fall in the 1st week of Oct, while the 3rd day of Oct 2021 starts the second week, and then the last day of October 2021,i.e. Oct 31, is the only day in the 6th week.
I had an automation task on hand in which I needed to pull data from the Power Query-generated pivot, so I had to implement a piece of code in VBA which calcs weeks the same.
Unfortunately, I couldn't find any prepared snippet, so after implementing I though it might worth sharing.
(Any comments and suggestions appreciated)
The DatePart function is perfect for this. Using DatePart with the interval set to "weeks" you can find the week of a given date. Then you subtract the number of weeks before the first day of that month (which sets the first day to week = 1).
Function WeekNumOfDate(D As Date) As Integer
WeekNumOfDate = DatePart("ww", D) - DatePart("ww", DateSerial(Year(D), Month(D), 1)) + 1
End Function
Here is a second version of the function that has the ability to set the FirstDayOfWeek argument:
Function WeekNumOfDate(D As Date, Optional FirstDayOfWeek As VbDayOfWeek = vbSunday) As Integer
WeekNumOfDate = DatePart("ww", D, FirstDayOfWeek) - DatePart("ww", DateSerial(Year(D), Month(D), 1), FirstDayOfWeek) + 1
End Function
As an example for using FirstDayOfWeek: With FirstDayOfWeek set to vbThursday, the date "Nov 5th, 2021" will return as Week 2, whereas it would by default be counted as Week 1. November 1st to 3rd of 2021 will be week 1, and then 4th to 10th will be week 2.
Its implementation in VBA is:
Function WeekOfMonth(My_Date As Date)
If Day(My_Date) > Day(My_Date - 1) And Weekday(My_Date) > Weekday(My_Date - 1) Then
WeekOfMonth = WeekOfMonth(My_Date - 1)
ElseIf Day(My_Date) > Day(My_Date - 1) And Weekday(My_Date) < Weekday(My_Date - 1) Then
WeekOfMonth = WeekOfMonth(My_Date - 1) + 1
Else
WeekOfMonth = 1
End If
End Function
Note that even though the above function is recursive, its time and space complexity is an expression of order N, which here cannot exceed 31.
I have a data set which includes dates.
I need to split this out by week number for reporting purposes.
What I have so far is:
startDate variable containing 03/01/2015 (populated from data in spreadsheet)
startDay = Day(startDate)
startMonth = Month(startDate)
startYear = Year(startDate)
startWeek = Application.WorksheetFunction.WeekNum(DateSerial(startYear, startMonth, startDay))
which gives me week 1 in startWeek
However I know need to know how far into week 1 the date is.
So for this example, as the date is the 3rd of January, it includes 3 days of week 1
Meaning the reporting I'm putting together will only report on 3 days (as opposed to the full week)
The only way I've figured to do this so far is to calculate which day of the year the date is and the use a MOD calculation (basically divide by 7 and the remainder is how far into the week it is)
dayNumber = DateDiff("d", DateSerial(startYear, 1, 1), DateSerial(startYear, startMonth, startDay)) + 1
dayOfWeek = dayNumber Mod 7
This does work, but I was wondering if there was a nicer solution than this.
You could use a loop to determine how many days before startDate the week number changed:
Public Sub FindDaysInWeekNo()
Dim startDate As Date
startDate = DateSerial(2015, 1, 3)
Dim startWeek As Integer
startWeek = Application.WorksheetFunction.WeekNum(startDate)
Dim i As Integer
Do While startWeek = Application.WorksheetFunction.WeekNum(DateAdd("d", -i, startDate))
i = i + 1
Loop
Debug.Print i '= 3rd day in this week number
End Sub
The following table shows my comparison to the other suggested formulas and why I think that (refered to =WEEKNUM) my calculation is correct.
Note that if you assume 1st to 7th January will be week 1 (days 1 to 7) you cannot use the WeekNum function because this will give you a different result (see table above and note that the first week has only 6 days according to the WeekNum function). Also you cannot name this week number (as what everybody calls week number is defined as https://en.wikipedia.org/wiki/Week#Week_numbering).
Instead you will need to use …
Public Function AlternativeWeekNum(startDate As Date) As Integer
AlternativeWeekNum = WorksheetFunction.Days(startDate, DateSerial(Year(startDate), 1, 1)) \ 7 + 1 'note that this no normal division but a integer division and uses a backslash instead
End Function
to calculate the week number your alternative way, and …
Public Function AlternativeWeekNumDay(startDate As Date) As Integer
AlternativeWeekNumDay = WorksheetFunction.Days(startDate, DateSerial(Year(startDate), 1, 1)) Mod 7 + 1
End Function
to calculate the day in the alternative week.
You can use the Weekday() function for this:
=WEEKDAY(B4;2)
The second parameter mentions how you want your days to be counted (starting from Sunday or Monday, counting starting from 0 or from 1, ...).
dayOfWeek = (8 + Weekday(startDate) - Weekday(DateSerial(startYear, 1, 1))) mod 7
Just take the positive mod 7 of the difference between the current Day-Of-Week and the Day-Of-Week for the 1st January of whatever the year is
I am trying to find the week number for a fiscal year which is starts on first sunday of February. I have got it to a point where I can get the week number which starts on first of every year (in my case feb).
Not able to start it from First Sunday. Below is what I've come up with.
=IF(AND(MONTH($E2)=2,DAY($E2)=1),1,ROUNDUP(($E2-DATE(YEAR($E2)-IF(MONTH($E2)<2,1,0),2,0)+WEEKDAY(DATE(YEAR($E2)-IF(MONTH($E2)<2,1,0),2,0)))/7,0))
I would also like it to end on Saturday of last week of the year.
For example: in Feb 2016, the week count should start from 7thFeb2016 and the count should end on 4thFeb2017.
Use this formula to find week number of given date:
=IF(A1>=IF(WEEKDAY(DATE(YEAR(A1),2,1),1)=1,DATE(YEAR(A1),2,1),DATE(YEAR(A1),2,7-WEEKDAY(DATE(YEAR(A1),2,1),1)+2)),ROUNDUP((A1-IF(WEEKDAY(DATE(YEAR(A1),2,1),1)=1,DATE(YEAR(A1),2,1),DATE(YEAR(A1),2,7-WEEKDAY(DATE(YEAR(A1),2,1),1)+2))+1)/7,0),ROUNDUP((A1-IF(WEEKDAY(DATE(YEAR(A1),2,1),1)=1,DATE(YEAR(A1)-1,2,1),DATE(YEAR(A1)-1,2,7-WEEKDAY(DATE(YEAR(A1)-1,2,1),1)+2))+1)/7,0))
I hope you want this.
UPDATED
If you want week number of fiscal quarter, use this:
=ROUNDUP(MOD(=IF(A1>=IF(WEEKDAY(DATE(YEAR(A1),2,1),1)=1,DATE(YEAR(A1),2,1),DATE(YEAR(A1),2,7-WEEKDAY(DATE(YEAR(A1),2,1),1)+2)),ROUNDUP((A1-IF(WEEKDAY(DATE(YEAR(A1),2,1),1)=1,DATE(YEAR(A1),2,1),DATE(YEAR(A1),2,7-WEEKDAY(DATE(YEAR(A1),2,1),1)+2))+1)/7,0),ROUNDUP((A1-IF(WEEKDAY(DATE(YEAR(A1),2,1),1)=1,DATE(YEAR(A1)-1,2,1),DATE(YEAR(A1)-1,2,7-WEEKDAY(DATE(YEAR(A1)-1,2,1),1)+2))+1)/7,0)),13.01),0)
I just chucked this together (no doubt there is a more elegant way to do this). You can use it by putting it into a Module in your VBA editor and then on the worksheet use the function =AltWeekNumber(E2)
Function AltWeekNumber(endDate As Range) As Date
Dim startDate As Date
startDate = FirstFebruarySunday(year(endDate.Value))
If startDate > endDate Then
startDate = FirstFebruarySunday(year(endDate.Value) - 1)
End If
AltWeekNumber = DateDiff("w", startDate, endDate.Value, vbSunday)
End Function
Private Function FirstFebruarySunday(year As Integer) As Date
For i = 1 To 7
If Weekday(DateSerial(year, 2, i)) = 1 Then
FirstFebruarySunday = DateSerial(year, 2, i)
Exit Function
End If
Next i
End Function
I am writing an AppleScript which generates an MS Excel spreadsheet every month. I need to know how many days are in the current month, then go trough all months and decide if a given day is a weekday or a holiday.
I suppose I would save holidays (from this web http://kalendar365.cz/statni-svatky/2016 as table and access them locally) for this.
My question is:
How do I get the last day in a month?
How do I efficiently loop trough all days in the current month and decide if it is Sunday, Saturday or a day specified somewhere else (for example, in a text file of xlsx spreadsheet)?
pbell's answer is promising, but the GetLastDay function doesn't work correctly for months that have fewer than 31 days; here's a function that fixes that:
# Returns the number of days in the month that the given date falls in.
# Example:
# my GetNumberOfDaysInMonth(current date)
on GetNumberOfDaysInMonth(aDate)
local aDateCopy
copy aDate to aDateCopy
set day of aDateCopy to 1
if month of aDateCopy is December then
set year of aDateCopy to ((year of aDateCopy) + 1)
set month of aDateCopy to 1
else
set month of aDateCopy to ((month of aDateCopy) + 1)
end if
return day of (aDateCopy - 1 * days)
end GetNumberOfDaysInMonth
The approach is based on setting the date to the 1st of the month, then incrementing the month (possibly rolling over into the next year), and subtracting 1 day, which works correctly with all dates, even in leap years.
How about a simple no-function-needed method?
set currdate to the current date
set nextmonth to currdate + (30 * days)
set {year:y, month:m, day:d, time:t} to nextmonth
set ms to m as string --month as string
set ys to y as string --year as string
set firstday to date (m & " 1," & y as string) --midnight at the first day of next month
set lastday to (firstday - 1) --minus one second
return lastday -- last day of the this month at 11:59 PM
As for weekends and holidays in Excel, doesn't Excel provide its own functions for that, as dirk-reichel mentioned?
However, if you want to use AppleScript to filter out these days using a pre-specified list of holidays, maybe this example will help. It loops through October through December of 2022, with USA holidays Halloween, Thanksgiving and Christmas Day specified. Note that Christmas Day happens to land on a Sunday in 2022.
set weekend to {"Saturday", "Sunday"}
set holidays to {date "October 31, 2022", date "November 24, 2022", date "December 25, 2022"}
set workdays to {}
set my_date to (date "Saturday, October 1, 2022 at 12:00:00 AM")
repeat
set dy to the weekday of my_date
set mydy to dy as string
if weekend does not contain mydy and holidays does not contain my_date then
set workdays to workdays & my_date
end if
set my_date to my_date + (1 * days)
if my_date contains (date "January 1, 2023") then --specify an end date for your loop
exit repeat
end if
end repeat
return workdays
The script below contains the 2 routines you're looking for : GetlastDay and isWorkingDay :
set myDate to current date -- just for example !
set N to GetlastDay(myDate)
log N --> number of days in month of myDate
set A to IsWorkingday(myDate)
log A --> true if Monday to Friday, false if Saturday/Sunday
on GetlastDay(LDate) -- return last day of month of LDate
copy LDate to L -- to not change LDate
set L's day to 32 -- = first day of next month
set L to L - (1 * days) -- last day of month
return day of L
end GetlastDay
on IsWorkingday(LDate) -- true if date is not Saturday or Sunday
set SD to weekday of LDate
return (SD is not in {Saturday, Sunday})
end IsWorkingday
I have a date with this format : 14w01 (year : 2014 week number : 1)
I want to convert this date in month like this : 14m01
Is there a function which converts a week number in a month number ?
Maybe something like this (in vba, not in formula) :
Format(weekNumber, "mm")
Thank you
It depends on how the weeks are defined. One way is to say that the first day of week#1 of a year is 1 January of that year. For this definition, a typical UDF is:
Public Function MonthFromDt(s As String) As Integer
Dim yr As Integer, wk As Integer, d As Date
ary = Split(s, "w")
yr = CInt(ary(0)) + 2000
wk = ary(1)
MonthFromDt = Month(DateSerial(yr, 1, 1) + 7 * (wk - 1))
End Function
There are other definitions of week number.
The DateFormat function is quiet comfortable, however the DateValue function, which parses a date, won't probably support your week format.
I suggest a trick with DateAdd, as DateAdd can handle weeks.
First split your date in year and week number:
Dim parts
parts = Split("2014w33", "w")
Dim year
Dim week
year = CInt(parts(0))
week = CInt(parts(1))
Then, add both to a "zero-date" to add up to the final date. Note that if you give "0" as year for DateAdd, VBA compiler interprets 2000.
dim DateResult
DateResult = dateAdd("yyyy", (year - 2000), DateValue("Jan 1, 0"))
Debug.Print dateResult
DateResult = dateAdd("ww", week, dateResult)
Debug.Print dateResult
Then show the result reformatted:
Debug.Print Format(DateResult, "yyyy\mm")
This prints on my side:
01.01.2014
20.08.2014
2014m08
August 2014, there is week 33 if I look up in the calendar. Seems correct.
I found a way to do it without VBA (and only using Formulas). This assumes A1 contains the "14w01" format
=LEFT(A1,2)&"m"&TEXT(MONTH(DATE(20&LEFT(A1,2),1,1)+(RIGHT(A1,2)*7)),"00")
Heres a breakdown of what the code does..
LEFT(A1,2) returns "14" (year)
MONTH(DATE(20&LEFT(A1,2),1,1)+(RIGHT(A1,2)*7)) converts the week # to the month # and it takes in the year 20&LEFT(A1,2) as well as week # RIGHT(A1,2)
TEXT(...,"00") pads the month # with a 0 if necessary (i.e. 3 becomes 03)
Then we just combine everything together to get "14m01"