package timeext

import "time"

func YearDifference(t1 time.Time, t2 time.Time, tz *time.Location) float64 {

	yDelta := float64(t1.Year() - t2.Year())

	processT1 := float64(t1.Sub(TimeToYearStart(t1, tz))) / float64(TimeToYearEnd(t1, tz).Sub(TimeToYearStart(t1, tz)))
	processT2 := float64(t2.Sub(TimeToYearStart(t2, tz))) / float64(TimeToYearEnd(t2, tz).Sub(TimeToYearStart(t2, tz)))

	return yDelta + (processT1 - processT2)
}