Take the fourth digit of what you currently are in. This number changes every year, and the next fourth digit is 0. Subtract this number by the second key of water. This can be obtained by knowin the first key. This key will be the 8th letter of the alphabet. Or the third key. This one is similar to the first key, but instead of 8 it is 15. Then add the third of the one before the beginning of the new day. If you forgot this digit, look at the circle with twelve numbers. Once having the number, add the number up of each other. The final number, will shine to you.