周数到月 [英] Week number to month

问题描述

鉴于我有一个特定年份的周数，如何获得本周开始的月份名称？ （使用Obj-c）

例如2009年第2周应转换为2009年1月
，2004年第51周转换为2004年12月

解决方案

找到答案有问题：获得一周的第一天

  //转换周到月
 int weekNum = sdi.mWeek; 
 const char * months [13] = {1月，二月，三月，四月，五月，六月，七月，八月，九月，十月，十一月，十二月，十一月}; 
 struct tm curYear = {0,0,0,1,0，sdi.mYear，0,0,0}; 
 time_t secsSinceEpoch = mktime（& curyear）+ weekNum * 86400 * 7; 
 struct tm * candidateDate = gmtime（& secsSinceEpoch）; 
 if（candidateDate-> tm_wday！= 1）
 {
 secsSinceEpoch + =（86400 *（candidateDate-> tm_wday-1））; 
 candidateDate = gmtime（& secsSinceEpoch）; 
} 
 // [months [candidateDate-> tm_mon]]返回月份
  

Given that I have the week number of a particular year, how do I get the month's name in which the week starts? (using Obj-c)

e.g. Week 2 of 2009 should convert to January 2009 and Week 51 of 2004 should convert to December 2004

解决方案

Found answer at question: get first day of given week

//convert week to month
    int weekNum = sdi.mWeek;
    const char *months[13]={"January","February","March","April","May","June","July","August","September","October","November","December","January"};
    struct tm curYear={0,0,0,1,0,sdi.mYear,0,0,0}; 
    time_t secsSinceEpoch=mktime(&curYear)+weekNum*86400*7;
    struct tm *candidateDate=gmtime(&secsSinceEpoch);    
    if (candidateDate->tm_wday!=1)
    {
        secsSinceEpoch+=(86400*(candidateDate->tm_wday-1)); 
        candidateDate=gmtime(&secsSinceEpoch);
    }    
    // [months[candidateDate->tm_mon]] returns month

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