转换iOS中系统时区中的任何时区日期

Question

我在将给定日期转换为iOS系统时区时遇到问题。

来源日期：2013-03-18 03:54:18 //其AM格式 目的日期应为：2013-03-18 03:30:15 //其PM格式。

我怎样才能得到这个？

我试过下面的代码，但得到错误的数据和差异了。

NSDateFormatter *fmt = [[NSDateFormatter alloc] init]; 
fmt.dateFormat = @"yyyy-MM-dd HH:mm:ss"; 
NSLog(@"Post date::%@",postDate); 
NSDate *utc = [fmt dateFromString:postDate]; 
fmt.timeZone = [NSTimeZone systemTimeZone]; 
NSString *local = [fmt stringFromDate:utc]; 
NSLog(@" local %@", local); 

NSDate *date1 = [NSDate date]; 
NSString *currentDateString = [fmt stringFromDate:date1]; 
NSDate *currentDate = [fmt dateFromString:currentDateString]; 
NSUInteger flags = NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit; 
NSDateComponents *difference = [[NSCalendar currentCalendar] components:flags fromDate:utc toDate:currentDate options:0]; 
NSLog(@"difference::%d",[difference day]); 
NSLog(@"difference::%d",[difference hour]); 
NSLog(@"difference::%d",[difference minute]); 

编辑：输出

Post date::2013-03-18 03:20:09 
local 2013-03-18 03:20:09 
difference::0 
difference::13 
difference::2 

Answer 1

NSString *openingHour = @"15:05:35 "; 
NSDateFormatter *workingHoursFormatter = [[NSDateFormatter alloc] init]; 
     NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:@"UTC"]; 
     [workingHoursFormatter setTimeZone:timeZone]; 
     [workingHoursFormatter setDateFormat:@"HH:mm"]; 
     NSDate *openingTime = [workingHoursFormatter dateFromString:openingHour]; 

你可以尝试对我的作品上面的代码，更改数据格式，您的需要

Answer 2

替换从您的代码...

fmt.timeZone = [NSTimeZone systemTimeZone]; 

像这样

fmt.timeZone = [NSTimeZone localTimeZone]; 

这将会为你工作。 ..