The manner in which dates are written is both inconsistent and confusing. Scholars believe Pierina to have done this deliberately to keep an unscrupulous folk who may get a hold of the cards from benefiting by foreknowledge they came by without permission.
For those interested in familiarizing themselves with Naturim, there is not much instruction available. JSD Johnston (a Naturim translator) has put together the Lexicarta 500 English-to-Naturim dictionary and offers a rudimentary course called Naturim for Non-Linguists through the online Omni Ocademy Annex.