Excel公式将月份增加一个，每周增加一个月(Excel formula to increase month by one and week in month by one)

 对于您似乎想要实现的目标，我建议使用InStr函数。 InStr将搜索一个字符串，并返回它首次出现的位置。 如果在搜索的字符串中没有搜索到的字符串，则返回0 。 
 
 以下是它的使用方法： 
 
InStr( [start], string, substring, [compare] )
 
 一个工作示例c / o 网上技术 ： 
 
InStr(1, "Tech on the Net", "the")
'Result: 9'

InStr("Tech on the Net", "the")
'Result: 9'

InStr(10, "Tech on the Net", "t")
'Result: 15'

InStr("Tech on the Net", "z")
'Result: 0'

For what you seem to be trying to achieve, I'd suggest using the InStr function instead. InStr will search a string and will return the position where it first occurs. If the searched for string does not occur within the string being searched, 0 will be returned.
 
Here's how it's used:
 
InStr( [start], string, substring, [compare] )
 
A working example c/o Tech on the Net:
 
InStr(1, "Tech on the Net", "the")
'Result: 9'

InStr("Tech on the Net", "the")
'Result: 9'

InStr(10, "Tech on the Net", "t")
'Result: 15'

InStr("Tech on the Net", "z")
'Result: 0'