Reconciling history and nature

Israel’s feasts both followed the agricultural calendar and reenacted Israel’s past. Passover, Pentecost and Booths celebrated various phases of planting, growth, and harvest.

Israel’s feasts reconciled nature with salvation history. The reconciliation was ritual, calendrical.

The dual calendar protected Israel from becoming a nature cult, and from becoming a purely spiritual body, detached from natural cycles. 

Put in modern terms: Israel was protected both from being essentialists and from being constructivists. Their calendar allowed neither stasis nor relativism. Their pattern of life harmonized natural cycles and social construction.

Big speculative question: What happens when Christians no longer keep a church calendar? What happens when we adopt a calendar based on national milestones rather than the events of redemptive history? Can we still reconcile nature and salvation history without a church calendar, or, absent a calendar, are we doomed to veer frenetically between naturalism and historicism?