Adds the specified number of years to a date or datetime value. This function will always return a valid date or datetime if the beginning date or datetime is valid. This function will always "roll" the centuries value as necessary. For example adding 100 years to "10 BC" will result in an AD date. However, adding more years than R:BASE can process will result in a null date. For example, adding 10 years to 1/1/9990, which would result in 1/1/10000 will result in a null value.
Using a negative INT will result in subtracting that many years.