While the counting of years and the year of the Ark myth is firmly established, the exact date when the Ark was found is based on pure speculation, and therefore the date of the new year is calculated purely based on ceremonial reasons. Usually it is the birth-date of the current king, but there are a few instances in recent history when this wasn’t so - during King Michaël, the date of the New Year was set to the discovery of Ark Island (corresponding to our mid-June), and the current New Year coincides with Pride’s Day of Bells. This day marks the beginning of the Lav rebellion, and is a holiday festivity across the Kingdom, in celebration of Lav’s victory over tyranny and oppression. It corresponds to our own late September.
There are no Santas or Christmas decorations in the Animal Kingdom, however, there is one tradition held for over three decades now - the Day of Bells is celebrated at noon by ringing all the bells in the entire Kingdom, which you will be able to experience yourself in the game (be careful about the volume on your earphones though!)
The Day of the Bells refers to the start of the rebellion, when Leopold's emmisary arrived at Pride. Usually, when royalty is at the door, the gate bells ring three times (and twice if it's nobility, and once if it's a non-noble delegation). When the bells end their ringing, the gates open. But the beller at Pride knew that something was wrong, that Leopold must have heard of Lav's quiet plot to overthrow him, and that opening the gate would probably lead to his imprisonment. So he rang once, twice, thrice... And just kept ringing, so the doors never open.
The royal delegation had not expected such a defiance, and, faced with a closed gate, turned back for Blackbark, while Pride armoured up for war. This day is thus considered the start of Lav's Rebellion, and the beginning of the end of Leopold's tyranny.