**Sure, I can help you with that!**
The issue with the current formula is that it adds one month to the original date if the day is greater than or equal to 15. This works for most cases, but not for dates like

**08/15/12** where the day is exactly 15.

To fix this, we can add an additional

- IF statement to check if the day is exactly 15.
- If it is, then we want to use the original date instead of adding a month.

Here's the updated formula:

Formula:

```
``````
=IF(DAY(A1)=15,A1,WORKDAY(DATE(YEAR(A1),MONTH(A1)+(DAY(A1)=15),16),-1))
```

This formula first checks if the day in A1 is 15. If it is, then it returns A1 (the original date). If it's not, then it uses the original formula to find the last working day on or before the 16th of the next month.

I hope that helps!