week-number

问题 I have a dataset with a date column. I want to get the week number associated with each date. I know I can use: x['date'].isocalendar()[1] But it gives me the week num with start day = monday. While I need the week to start on a friday. How do you suggest I go about doing that? 回答1: tl;dr The sections " ISO Standard " and " What you want " is to clarify your need. You could just copy paste the code in the section " Solution " and see if the result is what you want. ISO Standard Definition

问题 I have a dataset with a date column. I want to get the week number associated with each date. I know I can use: x['date'].isocalendar()[1] But it gives me the week num with start day = monday. While I need the week to start on a friday. How do you suggest I go about doing that? 回答1: tl;dr The sections " ISO Standard " and " What you want " is to clarify your need. You could just copy paste the code in the section " Solution " and see if the result is what you want. ISO Standard Definition

问题 I wish to label my data based on their week. This is my data: df2 <- structure(list(Order_Date = structure(c(16735, 16805, 16753, 16830, 17075, 17009, 17085, 16740, 16891, 16750, 16820, 16849, 16906, 16929, 16746, 16731, 16786, 16873, 16895, 16931), class = "Date")), .Names = "Order_Date", row.names = c(NA, -20L), class = "data.frame") and I tried to label them based on the week (0th week, 1th week and ....) and I wish to group my data by the week later And I tried this: # order by data

问题 In javascript, how can I find out how many weeks a given year has? Getting the weeknumber from year-dec-31 will fail since that can result in week 1. This question calculate number of weeks in a given year sort of answers it, but is there any neat way of calculating this in JS? 回答1: For the ISO 8601 Standard Weeks function getISOWeeks(y) { var d, isLeap; d = new Date(y, 0, 1); isLeap = new Date(y, 1, 29).getMonth() === 1; //check for a Jan 1 that's a Thursday or a leap year that has a /

问题 I'm surprised that I can't find any existing solutions to this online but I just need an SQL function that returns an ISO standard week number (i.e. the start of week 1 is always the first Monday of the year). None of the DatePart function options consistently return the correct result. I had thought the option "vbFirstFourDays - Start with the first week that has at least four days in the new year." but testing it for today (12th Jan) returns week 3, not week 2 (my expression is DatePart("ww

问题 I am trying to get both week number and year from a date object in R. Until then, I did it separately : I used isoweek() function to extract week and year() function to extract year. So that my data.frame has 3 variables : date, week, year This is working except for beginning/end of year : for example, 2015 has 53 weeks and January 1st, 2016 belongs to the 53rd week of 2015 ... but with my code, it is such that 1/1/2016 is week 53 but year 2016 whereas I would like it to be week 53 in year

问题 I am trying to get both week number and year from a date object in R. Until then, I did it separately : I used isoweek() function to extract week and year() function to extract year. So that my data.frame has 3 variables : date, week, year This is working except for beginning/end of year : for example, 2015 has 53 weeks and January 1st, 2016 belongs to the 53rd week of 2015 ... but with my code, it is such that 1/1/2016 is week 53 but year 2016 whereas I would like it to be week 53 in year

问题 I have a simple situation where I have a user supplied week number X, and I need to find out that week's monday's date (e.g. 12 December). How would I achieve this? I know year and week. 回答1: Some code based mainly on previous proposals: $predefinedYear = 2009; $predefinedWeeks = 47; // find first mоnday of the year $firstMon = strtotime("mon jan {$predefinedYear}"); // calculate how much weeks to add $weeksOffset = $predefinedWeeks - date('W', $firstMon); // calculate searched monday

问题 Originating from this question gnuplot why warning: Bad time format in string, there was the finding that the week numbers in gnuplot using the time specifiers %W and %U are wrong in some cases. Apparently, there are different definitions of the week numbers. Furthermore, there are different definitions when a week starts, e.g. on Sunday or Monday. One definition for week numbers, which is commonly used (however, not in the US and a few other countries) is according to ISO 8601. Code: (to

问题 Originating from this question gnuplot why warning: Bad time format in string, there was the finding that the week numbers in gnuplot using the time specifiers %W and %U are wrong in some cases. Apparently, there are different definitions of the week numbers. Furthermore, there are different definitions when a week starts, e.g. on Sunday or Monday. One definition for week numbers, which is commonly used (however, not in the US and a few other countries) is according to ISO 8601. Code: (to