NSTimeInterval timeInMiliseconds = [[NSDate date] timeIntervalSince1970];@H_301_10@ 
 
要改变它,@H_403_4@ 
  
 
NSDate* date = [NSDate dateWithTimeIntervalSince1970:timeInMiliseconds];@H_301_10@ 
 
按照apple documentation,@H_403_4@ 
 
NSTimeInterval：用于指定时间间隔(以秒为单位).@H_403_4@ 
 
typedef double NSTimeInterval;@H_403_4@ 
 
它是double型.@H_403_4@ 
 
要将日期转换为字符串,@H_403_4@ 
  
 
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss zzz"];

//Optionally for time zone converstions
[formatter setTimeZone:[NSTimeZone timeZoneWithName:@"..."]];

NSString *stringFromDate = [formatter stringFromDate:myNSDateInstance];

[formatter release];@H_301_10@