Just get this thing straight and do not change the date of your iPhone to 1st January, 1970. That is it. It is very simple thing to. All you have to do is do nothing. Do not let curiosity take over you, because it will get your device bricked. And an iPhone is quite a device that you want keep going.
To let you know more, let just say that the rumors originated as a prank from 4Chan. You will not be able to have the retro Apple Inc. logo, if you try to set the date on your device to 1970. Your iPhone is just a smartphone, not a time machine. Instead, what will happen is that your device will be dead and you would not want that to happen.
The prank trick actually was started off at 4Chan and was initially aimed at the 5S devices and above. The prank stated that in case, you change the date of your device to 1st January, 1970; you will be able to sport the retro Apple Inc. logo. You just had to change the date, and then press down the power button and reboot your device. Once you do it, it is done. This is originally an Ester Egg that drains out all your battery. The date is specific because that is date of the Unix Epoch. The Easter egg completely drains out our battery and your device is left dead.
On the other hand, there is some good news for Apple Fan boys as well. Reports suggest that Apple Inc. is launching a new iPhone and iPad very soon. The reported device is iPhone 5SE, while we will get another model of iPad Air. The new iPhone 5SE is going to be a 4 inch device with the hardware upgrades that can be compared to that of iPhone 6 and 6S.