I want to select a date that gives me 18 months from the current date, but I am not getting exactly 18 months.

Before Running the query, min and max dates are.

MIN Date: 02/22/2018

MAX Date: 03/26/2021

Query

```
SELECT DATEADD(dd,-548,cast(GETDATE() as datetime));

```

Above query returns the min date as 10/15/2019. So from 10/15/2019 to 03/26/2021 is 17 months and 12 days. While my expectation is to get 10/05/2019 from this query so that I get exactly 18 months or 548 days.