Lily's Time ward and TCC was magical masterpiece of its time, technology used in it was years ahead of its time and miracle but at start what she discovered was just incomplete time rune that was good at fireworks .thankfully she recognized rune was related to time magic but for months her search for related materials remained fruitless in magical side .

While reading on non magical history she found about Einstein a science who had roll in innovation of atom bomb. This lead her to theory of relativity and relation between space,time and matter.

She was able to recognized that simple time alteration will not work so she combined space expansion charm with it to create a subspace that is independent of outside world . This could only work on closed system and requires lots of support for air and lights thus not suitable for large scale.

Everyone in tha group started to explore TCC and its limitations. They found that

1. TCC can overlap but time compression does not change thus it is possible to create multiple time compression zones inside single TCC .

2. Power required to start TCC depends on area need to cover and power required to maintain TCC depends on environmental maintenance of the area thus not suitable for open air.

3. As TCC required subspace it is difficult to operate it is difficult to operate it continuously for more than 3 days of outside time.

4. It can operate between time compression of 1:10000 to 10000 :1 but Anything with more than 438 time difference required exponentially more power to operate.

5. Time ward can create impenetrable shield form outside world and cut most of connection from outside.

6. It is only possible to teleport in or out of ward with elves and fae magic .

7. TCC that lily used did affect aging process of living cells . Emma was able to modify it so that it stop cell from aging.

Dan pointed that they can create a time ward on island with minimal time difference when they require shielding from outside and create time pockets in school to speed up learning thus entire school, libraries and farm had TCC installed. Every TCC was synchronize and set at 365 :1 compression ratio.

Everyone would enter TCC at evening and exit after 12 hours everyday thus gaining extra 6 months of time. Students learn everyday subjects that are helpful in fighting against Dumbledore and all basic subjects and skills of both side of the world.

While in TCC harry research into time magic and realized that they have no way to detect or prevent use of time turners so they planed to infiltrate department of mystery for any information on time magic

This was problems they have to solve before Dumbledore finds out about anything.

Harry and Everyone else created illusion that Dumbledore expected to see while exploring their limits