moment.js how to set startOf week to monday on current week? - node.js

I want to make the date of startOf("week") its start from Monday on current week
Is it possible for make this? My code:
moment().startOf("week").toDate();
This startOf start from saturday proof startOf start from saturday

Take a look at the First Day of Week and First Week of Year section
From the docs (emphasis is mine)
Locale#week.dow should be an integer representing the first day of the week, 0 is Sunday, 1 is Monday, ..., 6 is Saturday.
So just by running this code before doing any calls to moment
// From 2.12.0 onward
moment.updateLocale('en', {
week : {
dow : 1
}
});
It will set the first day of the week to Monday.
After that calling moment().startOf("week").toDate() will give you a Monday.

Related

how to calculate the date from the year, week-of-year and day-of-week in EXCEL?

I have the Year, Week-of-Year and Day-of-the-Week as follows:
Year = 2022 (A2) ; Week Year = 35 (B2); Week Day = 4 or Thursday (C2)
and I would like to estimate the Date as dd.mm.yyyy, which is highlighted in yellow as it shows in the EXCEL picture.
I tried many formulas, but I am sure there might be an easy one.
I think you are counting the weeks starting from zero because for 9/1/2022 (YYYY/MM/DD format) the corresponding week is 36 as per the result of function WEEKNUM(DATE(2022,9,1)). In order to use the logic to multiply the number of weeks by 7. You need to use as a reference the first day of the year, if it was a Sunday, if not then go back to the previous Sunday, so you can count the entire week. Bottom line use as a reference date, the Sunday of the first week of the year, not the first day of the year (YYYY/1/1)
Here is the approach we use in cell E2:
=LET(y, A2:A6, wk, B2:B6, wDay, C2:C6, fDay, DATE(y,1,1), seq, SEQUENCE(7),
fDay - IF(WEEKDAY(fDay)=1,0, WEEKDAY(fDay,2)) + 7*wk
+ XLOOKUP(wDay, TEXT(seq,"dddd"), seq-1))
We use the LET function to avoid repeating the same calculation. The following expression finds the previous Sunday if the first day of the year (fDay) was not a Sunday:
fDay - IF(WEEKDAY(fDay)=1,0, WEEKDAY(fDay,2))
The XLOOKUP function is used to get the numeric representation of the weekday and use the TEXT function to generate the weekdays in a long format. Since we count the entire week, if the weekday is a Sunday (column C in my screenshot), then we don't need to add any day to our reference date, that is why we use seq-1.
Here is the output for several sample data. Assuming the week count starts with zero, if not the formula needs to be adjusted as also the input data.
Notice that the year 2021 started on a Friday, so if we want to find a day for the first week (0) before Friday it will return a date from the previous year. Like in the case of Monday. If you want an error message instead, then the formula can be modified as follow:
=LET(y, A2:A6, wk, B2:B6, wDay, C2:C6, fDay, DATE(y,1,1), seq, SEQUENCE(7),
result, fDay - IF(WEEKDAY(fDay)=1,0, WEEKDAY(fDay,2)) + 7*wk
+ XLOOKUP(wDay, TEXT(seq,"dddd"), seq-1),
IF(YEAR(result) <> y, "ERROR: Date from previous year", result))
I found the solution:
Year = 2022 (A2) ; Week Year = 35 (B2); Week Day = 4 or Thursday (C2)
=DATE (A2,1,3)-WEEKDAY(DATE(A2,1,3)) + 7 * B2 + C2 - 6
I found this solution, but you need to do further testing if it really works.
I calculate month from week: =+MONTH(DATE(YEAR(A2);1;1)+B2*7-1)
I calculate week day number from week day name: =MATCH(D2;{"Monday";"Tuesday";"Wednesday";"Thursday";"Friday";"Saturday";"Sunday"};0)
And then make date using: =DATE(A2;C2;E2)

how to set SimpleDateFormat W use Monday as the first day of the week instead of Sunday (US default)

how to set SimpleDateFormat "W" use Monday as the first day of the week instead of Sunday (US default)
I'm trying to extract the week of the month number with F.date_format("dates", "W")
but this would make an observation on the Sunday the first of week 2 instead of the last of week 1
The issue seems to be because simple date format isn't localised and defaults to us/default
Is there a way to set the locale to en/gb for simpleDateFormat to not treat use US defaults
https://issues.apache.org/jira/browse/SPARK-31879

Get the first Friday of the Quarter of Today's Date

I was trying to get the first Friday of the quarter of today's date or any given date. Let's say the date is 12/06/2020, which falls to the 2nd quarter of the year. I should be able to get the first Friday of the 2nd Quarter and that should be April 3rd.
I was only been able to get the quarter of a given date, which you can see in the code below. Been stuck here for a while. Thanks in advance.
quarter = Int((Month(Now) + 2) / 3)
Here's a function that takes a date and returns the first Friday of the quarter:
Function FirstFridayOfTheQuarter(MyDate As Date) As Date
Dim FirstDayOfTheQuarter As Date
FirstDayOfTheQuarter = DateSerial(Year(MyDate), Int((Month(MyDate) - 1) / 3) * 3 + 1, 1)
FirstFridayOfTheQuarter = DateAdd("d", (13 - Weekday(FirstDayOfTheQuarter)) Mod 7, FirstDayOfTheQuarter)
End Function
This function is taking advantage of the Weekday function that returns:
1 for a Sunday
2 for a Monday
3 for a Tuesday
4 for a Wednesday
5 for a Thursday
6 for a Friday
7 for a Saturday
In case you want a non VBA solution:
My formula is:
=CEILING(EOMONTH(DATE(YEAR(A1);ROUNDUP(MONTH(A1)/3;0)+(ROUNDUP(MONTH(A1)/3;0)-1)*2;1);-1)-5;7)+6

Find fourth Thursday each month and if NASDAQ closed that day, take next day

I am working in Excel where I need to find the fourth Thursday in each month but if on that day NASDAQ is closed take the day after. I have this formula for each fourth Thursday:
=DATE(YEAR(A2),MONTH(A2),CHOOSE(WEEKDAY(DATE(YEAR(A2),MONTH(A2),1)),26,25,24,23,22,28,27))
but I am not be to get the next business day where the fourth Thursday is any one of:
01-Jan-14
20-Jan-14
17-Feb-14
18-Apr-14
26-May-14
03-Jul-14
04-Jul-14
01-Sep-14
27-Nov-14
28-Nov-14
24-Dec-14
25-Dec-14
Please try appending to your formula:
+IF(OR(A2=41823,A2=41970,A2=41998),1,0)

how to calculate the number of the week in a year?

I would like to calculte the number of the week in a year. I see this post
In this post the acepted answer use this code:
public static int GetIso8601WeekOfYear(DateTime time)
{
// Seriously cheat. If its Monday, Tuesday or Wednesday, then it'll
// be the same week# as whatever Thursday, Friday or Saturday are,
// and we always get those right
DayOfWeek day = CultureInfo.InvariantCulture.Calendar.GetDayOfWeek(time);
if (day >= DayOfWeek.Monday && day <= DayOfWeek.Wednesday)
{
time = time.AddDays(3);
}
// Return the week of our adjusted day
return CultureInfo.InvariantCulture.Calendar.GetWeekOfYear(time, CalendarWeekRule.FirstFourDayWeek, DayOfWeek.Monday);
}
However I see a problem. The number of the week is repeated if the last day of a month is in Sunday.
For example, the last day of March of 2013 year is in sunday. This week is the number 13th, is correct. But in April, how C# use always 6 weeks in a month to calculate the number of week, the first week of april has not any day of april, because all the days belong to march because the last day of the week is 30th March. So C# says that the first week of april is th 15th week, but this is incorrect, it has to be 14th.
So I would like to know if there are any way to calculate the number of a week in a right way.
EDIT:
I mean this:
In march, the last week is this:
25 26 27 28 29 30 31
This is the 13th, is correct.
In april, the first week is:
1 2 3 4 5 6 7
And this week is calculated as 15th.
So if I see the march calendar the last week is calculated as 13th and if I see the april calendar the last week of march is caluclated as 14th. This is incorrect.
SOLUTION:
DateTime dtCalendar = Calendar.DisplayDate;
int gridRow = (int)GetValue(Grid.RowProperty);
// Return the week of our adjusted day
int wueekNumber= System.Globalization.CultureInfo.InvariantCulture.Calendar.GetWeekOfYear(dtCalendar, System.Globalization.CalendarWeekRule.FirstDay, DayOfWeek.Monday);
if (dtCalendar.DayOfWeek == DayOfWeek.Monday)
{
gridRow = gridRow - 1;
}
Text = (weekNumbe r+ gridRow - 1).ToString();
Thanks.
The problem is that you are using the wrong CalendarWeekRule. To get the result you want you should use FirstDay. I have seen various codes in internet saying that you should use FirstFourDayWeek but, after some testing, I realised that the "right one" is FirstDay. I have tested it with your example and it delivers the right result: 14th week.
int targetYear = 2013;
DateTime targetDate = new DateTime(targetYear, 4, 1);
int week = System.Globalization.CultureInfo.CurrentCulture.Calendar.GetWeekOfYear(targetDate, System.Globalization.CalendarWeekRule.FirstDay, DayOfWeek.Monday);

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