用批处理实现文件备份器V2.3

echo           │    31个；                                              │
echo           │                                                        │
echo           │        3. 字母式的日期只能是 M,T,W,Th,F,S,Su 中的      │
echo           │                                                        │
echo           │    任意几个，不区分大小写；                            │
echo           │                                                        │
echo           │        4. 日期之间只能用逗号分隔。                     │
echo           │                                                        │
echo           │                                                        │