Subtract n months from datetime [Why?]

[Paulo da Silva]

Às 05:29 de 21/06/22, Paulo da Silva escreveu:

As a general response to some comments ...

Suppose we need to delete records from a database older than ...
Today, it's usual to specify days. For example you have to keep some gov 
papers for 90 days. This seems to come from computers era. In our minds, 
however, we immediately think 90 days=3 months.
For example, one may want to delete some files older than 9 months. It's 
far more intuitive than 270 days.
When we talk about years it is still going. For example I need to keep 
my receipts for 5 years because IRS audits.
Accepting this, it's intuitive, for example, that 3 months before July, 
31 is April, 30.
The same happens for the years. 5 years before February, 29 is February, 28.

Again, this is my opinion and that's the way I like it :-)
Regards
Paulo