提前一天：

NSArray *dataArr = [CommonTool getDatesWithStartDate:@"2020-12-05" endDate:@"2020-12-10"];

// iOS获取两个日期之间的所有日期数组，精确到天
+ (NSArray*)getDatesWithStartDate:(NSString *)startDate endDate:(NSString *)endDate {
    
    NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier: NSCalendarIdentifierGregorian];
    
    //字符串转时间
    NSDateFormatter *matter = [[NSDateFormatter alloc] init];
    matter.dateFormat = @"yyyy-MM-dd";
    NSDate *start = [matter dateFromString:startDate];
    NSDate *end = [matter dateFromString:endDate];
    
    NSMutableArray *componentAarray = [NSMutableArray array];
    NSComparisonResult result = [start compare:end];
    NSDateComponents *comps;
    while (result != NSOrderedDescending) {
        comps = [calendar components:NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay |  NSCalendarUnitWeekday fromDate:start];
        [componentAarray addObject:start];
        
        //后一天
        [comps setDay:([comps day]+1)];
        start = [calendar dateFromComponents:comps];
        
        //对比日期大小
        result = [start compare:end];
    }
    return componentAarray;
}