Thank you for this incredibly helpful feedback! You've pinpointed the exact areas that need clarification. I'm currently reworking the entire system and layout to address these points.
To answer your question directly: in the original version, the "Calendar Cypher" was indeed just the day-of-the-month number (e.g., 5 for Oct 5th), which you then used in the calculation to get your final roll. Your confusion is completely valid, and the terminology will be much clearer in the next version.
The new structure will feature a much simpler core ruleset. I've just released a "Theater of Mind" version that strips away the stat tracking for a purely narrative focus, and the "Calendar Cypher" will be refined as a separate edition for those who want that specific kind of randomness.
Your insights are invaluable, thank you for sharing them