Demo users can play full version for free

Demo users can play full version for free

I made a Minecraft account for my sibling, just to play demo mode.
I Opened the Minecraft launcher and put the modded 1.6.4 (
1.6.4-Forge9.11.1.965) and played. When the menu showed, It showed: Multiplayer, and Single Player. I already had a Paid account, so I know what the Minecraft menu would look like. I Opened The Single Player, and it showed the world list. I made a new world and it did not show the 100 min. timing.

I download Minecraft Forge, just to play my favorite mods using my account. when I used forge on the demo user, it showed the full version.

1.Download Minecraft Forge (forge-1.6.4-9.11.1.965-installer)
2.download mod using the installer
3.log in the Minecraft launcher with a demo account
4.use user "Forge"
5.Play and you will see