Substract hour into a function

[ApocalypSys]

Hi, I need to substract a variable hour from a timestamp in PostgreSQL 8.2, I think I can use the following sentence

select '2007-05-14 12:36:47' + ('-5 hours'::reltime);

I try that line in console and works fine for my purposes, but I'm having troubles turning the '-5' into a parameter for a plpgsql function.

Do you have any recommendations about how this can be done?



PS: This is my first post, I hope I accomplish all the posting guidelines, any comment is welcome.

[michaelb]

Welcome to the Forum!
Let's start with the code you've developed so far for your function.
Post it here; no matter how bad it can be at this point, we'll just use it as a launch pad.