How can I generate a random number between 1 and x (where x is quite small) based on a seed? [JavaScript]

I am currently trying to create a basic (locally hosted) webpage which displays a random image from a folder, with the image changing each day.

To do this, I have put all of the images into a folder and have given them the names 0001, 0002, 0003, ..., . I am now trying to create a random number generator which will generate the same number on a particular day, but on the next day will generate a totally different number. This random number will be used to select the image.

I have tried doing this using the following JavaScript:

var d = new Date();
var seed = Math.floor(d.getTime()/(1000*60*60*24));
var randID = Math.abs(Math.floor(Math.sin(Math.log(seed))*8));

However, incrementing the value of the seed does not have much of an effect on the variable randID, so this is not a possible solution.

Can anyone help me to understand how this might be done?

Note that it is important that the random numbers generated are uniformly distributed (or at least close).