NSString *timeStr = _model.serverTime;
timeStr = [timeStr substringToIndex:10]; // 返回值一般有毫秒,忽略掉毫秒
NSDate *detaildate=[NSDate dateWithTimeIntervalSince1970:[timeStr doubleValue]];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"MM/dd HH:mm"];
NSString *currentDateStr = [dateFormatter stringFromDate: detaildate];
// currentDateStr时间戳转换而来的时间字符串