Well, your solution works. But if you want to subdivide the season into neat and regular weeks, it’s not possible. So the next best thing is subdividing the year into weeks while disregarding the seasons.

Don’t subdivide the 73-day seasons.

Instead, subdivide the year into 73 5-day weeks.

A year made up of 5 seasons and 73 weeks.

Which is also why I hate that our calendar starts at year 1.

Not if you divide by 5. It gets you 73 days each.