My insight:

• Europe: Early winter
• In USA: Late autumn or early winter
• Asia (ex-China, Japan): Late winter or early spring
• China: Spring
• Japan: Winter
• Latin America: Late winter or early spring
• Middle East, Arab countries: Mid winter

What is the Kondratiev Cycle or Wave?

Kondratiev waves (also called supercycles, great surges, long waves, K-waves or the long economic cycle) are described as sinusoidal-like cycles in the modern capitalist world economy.^[1] Averaging fifty and ranging from approximately forty to sixty years in length, the cycles consist of alternating periods between high sectoral growth and periods of relatively slow growth. Unlike the short-term business cycle, the long wave of this theory is not accepted by current mainstream economics.

Source: Wikipedia