Which measurement of a year is defined as the time between successive crossings of the vernal equinox and dictates seasonal length?

Answer

The tropical year

The tropical year is defined by the time it takes for the Sun to complete a cycle between successive vernal equinoxes. This period, lasting approximately 365.242 mean solar days, is the basis for seasonal alignment and calendar construction.

Which measurement of a year is defined as the time between successive crossings of the vernal equinox and dictates seasonal length?

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The Ecliptic: Crash Course Kids #37.2 - YouTube

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