Isn't it Autumn?
In western society, our calendar (Gregorian) is based on the movement of the planet around the sun. It is specifically designed so that the time from one fixed point, such as a solstice or equinox, to the next is called a tropical year. Our seasons are then tied to these opposing solstice (winter and summer) and equinox (spring and autumn).
Living in China, I have been intrigued by the fact that the change in season - now Summer to Autumn - is declared by the government. It's not based on the relationship of the sun to our planet, or even under the Chinese Lunar calendar, the relationship of the moon to our planet. Rather the change in season is based upon having a specific number of days in below (or above) a certain temperature. Seems really quite practical, especially when policy is tied to the season - that is, when it's ok to turn on and off heaters and air-conditioners.
Many writers talk about the "seasons of life" - the autumn is usually depicted as the time after children leave the home, when we are harvesting our fields, when we are enjoying the fruits of our labor. The calendar (or your age) may define this to be spring, summer, autumn or winter of your life. Perhaps an authority defines the season; for example, companies have expectations of ages to do certain kinds of roles or even clear requirements on when you must retire. Maybe the season is defined by your actions.
Though I wonder, should the season be defined by you, your thoughts and attitude?
For a bit more on Autumn in China, see www.readsolutionsgroup.com/travelblog.html.
For more on calendars, enjoy the website webexhibits.org/calendars/index.html.