How to generate a random number from system clock as seed

[Eric P626]

I managed to create a random number generator using the following 
code:

~~~
auto rng = Random(42);
//....
uniform(0,10,rng);
~~~

Now I want to seed the generator using system time. I looked at 
Date & time functions/classes and systime functions/classes. The 
problem is that they all require a time zone. But I don't need a 
time zone since there is no time zone. I just want the number of 
seconds elapsed since jan 1st 1970. In other words, the internal 
system clock value.