Last day of September. The days have gotten shorter, the warmth of the day has become cooler and the waning of the year is coming.
This idea of having someone who controls that sort of thing came to me some years ago and I drew up what this character should look like in one of my sketchbooks. Looking as though he'd seen it all and was just waiting for one slip up to bring the year into the first part of winter, where everything would be shut down for a while. The wings on his head are to indicate how time flys by so quickly.
The characters in the background are meant to be helpers, even though they look somewhat evil.