Forum Discussion
How to create a field in Access 2016 table that shows the month based on a date in another field?
DON'T DO THAT. It's a bad design pattern. That's what has to happen in Excel spreadsheets, which lack the tools for relational database application design. When you use Access to store and use your data, you follow the rules of relational database application design, not the rules of Excel spreadsheet design.
So, invest some time in learning how relational databases work. It's based on the principles of Normalization. This is one good starting point, but a quick Bingoogle search will turn up many more. Once you have a better foundation with the tools of table design, you'll understand why adding new fields is such a bad design approach.
If you care to explain WHY you wanted to do this, someone can help you come up with a more appropriate approach.