Why do PostgreSQL examples say `+ integer '7'`? The PostgreSQL date functions documentation contains the following example:

date '2001-09-28' + integer '7'


Why does it consist of converting a string to an integer? Why not phrase it like this:

date '2001-09-28' + 7


Is there some tangible reason why integer '7' is preferable to plain old 7?
Interesting question, and I don't know the answer.  My best guess is that all the other examples use the same way of casting, and someone thought it is better having it consistent.  If you are pissed off irked by this, you can scroll to the bottom of the page and send a complaint using the form linked there.