From Tempus Fugitive:
WELLS: You see, the twenty-second century is a peaceful, harmonious Utopia.
And:
Utopia was founded by Superman's descendants.
So, I believe it was some time in the twenty-one century, but afraid there isn't not an accurate date.
TEMPUS: One of the many disadvantages of being from Utopia is we have a complete lack of technological understanding.
[...]
No one works, no one argues, there are nine thousand channels and nothing on!
By the way, sometimes I have to agree with Tempus. What kind of society was that? A bunch of new hippies that worship their founders and spend their time obsessing about them and brainwashing the children to perpetuate the cult?
How did Lois Lane's brood come to this?
It seems they took some ideals too far.
Maybe somebody can write the Chronicles of Utopia, telling how it came to be.
Andreia