date_add (days) function
Applies to: 
Databricks SQL Databricks Runtime
Returns the date numDays after startDate.
To add units other than days, use date_add(unit, value, expr)).
Syntax
date_add(startDate, numDays)
Arguments
startDate: A DATE expression.numDays: An INTEGER expression.
Returns
A DATE.
If numDays is negative abs(num_days) are subtracted from startDate.
If the result date overflows the date range the function raises an error.
Examples
> SELECT date_add('2016-07-30', 1);
2016-07-31