After a lengthy discussion amongst both DMs and Developers, we have come to a decision regarding how much time has passed. While the day/night cycle as well as seasons are rather rapid, we decided it would still be easier for plot progression and NPC/PC development to keep time flowing at the rate of the real world.
In other words, for every year in real life that passes, one year has passed in the game world.
Thus, three years have passed in total since we have opened up the server, both in real years AND game years.