Own Calendar System and Number System and Legends and Histories

In a Nutshell:
Earth time = 5 Agrarus / 225 Minecraft days
Agrarus = 5 Lunaris / 45 Minecraft days 
Lunaris = 9 Minecraft days, also 1 Moon cycle

Date Format example:
EARTHTIME AGRASUS NR-DAY DAY
I Herobrinius, IL Oraculatag
HIE Dimensionis, IE Librariustag

Date can be written by books, paper, anything writeable.
Descriptions are legends or stories. Maybe it can have effects.

1 Lunaris

1 Agrasus

Numbers: