JSON日期NSDate的結果爲零

Question

我有一個JSON格式，看起來像這樣的日期字符串：2014-02-07T00:00:00+08:00

而且我試圖把它與格式MM/dd/yyyy轉換爲NSDate。

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init]; 
[dateFormat setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss.SSS"]; 

NSDate *date = [dateFormat dateFromString:datestring]; 
NSDateFormatter *newDateFormatter = [[NSDateFormatter alloc]init]; 
[newDateFormatter setDateFormat:@"MM/dd/yyyy"]; 

NSString *newString = [newDateFormatter stringFromDate:date]; 
NSLog(@"Date: %@, formatted date: %@", date, newString); 

但是結果是零。怎麼了？

Answer 1

正確的日期格式是：

[dateFormat setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssxxx"]; 

或

[dateFormat setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZZZZZ"]; 

參見：ICU Formatting Dates and Times

NSString *datestring = @"2014-02-07T00:00:00+08:00"; 

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init]; 
[dateFormat setDateFormat:@"yyyy-MM-dd'T'HH:mm:sszzz"]; 
NSDate *date = [dateFormat dateFromString:datestring]; 
NSDateFormatter *newDateFormatter = [[NSDateFormatter alloc]init]; 
[newDateFormatter setDateFormat:@"MM/dd/yyyy"]; 
NSString *newString = [newDateFormatter stringFromDate:date]; 
NSLog(@"Date: %@, formatted date: %@", date, newString); 

的NSLog輸出：

Date：2014-02-06 16:00:00 +0000，格式化日期：02/06/2014