转换日期格式 年／月／日 ／星期

NSDateFormatter *timeFormatter = [NSDateFormatter new];

[timeFormatter setDateStyle:NSDateFormatterFullStyle];

NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:@"zh"];

[timeFormatter setLocale:locale];

timeFormatter.dateFormat = @"yyyy/MM/dd EEE";

NSDate * date = [NSDate date];

NSString * str= [timeFormatter stringFromDate:date ];