把当前时间(NSDate)转为字符串 - 获取当前时间的Day

1.把当前时间转为字符串 (NSDate与北京时间相隔8小时,格式化之后就是北京时间)
　　 NSDate *date = [NSDate date];
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc]init];
    [dateFormat setDateFormat:@"yyyy/MM/dd HH:mm:ss"];
    NSString *dateStr = [dateFormat stringFromDate:date];
    NSLog(@"当前时间:%@",dateStr);

2.获取当前时间的Day
+ (NSInteger)getCurrentDay{

    NSDateComponents *components = [[NSCalendar currentCalendar] components:NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit fromDate:[NSDate date]];
    NSInteger currentDay = [components day];
    return currentDay;
}