All of the examples I can find for adding a number of minutes to a timestamp show the number of minutes being hard-coded in the query. I have a table that has a column containing a starting time and another column containing the number of minutes until the process will be finished. I want to add the starting time and the number of minutes to calculate the finish time. How do I convert the minutes column from an int4 to an interval? Or is there a different way I should do that?