Create a "random" number between range without any module except time

I would like to create myself a "random" number generator between 2 edges. Moreover, I would like to create the same thing but with float numbers between two edges (like the random.random but of the range I want).

Time is required for me for timestamps.

I am currently learning the way random numbers are generated (I am using this way with timestamp as a start):

a = int
b = int
m = int
number = time.mktime (time.localtime ())

for x in range (0, m):
    number = (a*number + c) % m
    print (number)

(int can be any integer number. There are multiple ways to optimize the returned values (to long to explain here))

This is the way I've learnt to have "random" integers. I am currently searching for a way to solve the problem above using this way (if possible). Any ideas?