Most flight plans release here are seasonal.
As they are mainly for business jets that fly on ad hoc basis, it isn't possible to release upcoming seasonal plans, instead they are based on past flights.
The plans are therefore split in to the following seasons:
Winter, starting October 1st and ending March 31st.
Spring, starting January 1st and ending June 30th.
Summer, starting April 1st and ending September 30th.
Autumn, starting July 1st and ending December 31st.
