Linked from

The 32 pages that link to Tropical year, each with the reason it gives.

• Julian calendarRelated: The Julian year's 365.25-day average exceeds this seasonal cycle.

• Lunar calendarRelated: It is the seasonal cycle that purely lunar years fail to match.

• Hebrew calendarRelated: The calendar's leap months keep festivals tied to the seasons of this year.

• Chinese calendarRelated: Its seasonal cycle is the solar reference the calendar must track.

• EquinoxRelated: The equinox provides the reference point used to define this year.

• IntercalationRelated: It supplies the seasonal cycle that intercalation keeps a calendar near.

• Leap yearRelated: Its fractional length creates the need for periodic calendar correction.

• CalendarRelated: Calendars tied to seasons must approximate this non-integer number of days.

• Axial precessionRelated: Precession makes the tropical year slightly shorter than the sidereal year.

• Lunisolar calendarRelated: The calendar must track this cycle to keep months in their seasons.

• Metonic cycleRelated: Nineteen tropical years differ from 235 lunar months by only about two hours.

• Precession of the equinoxesRelated: Its reference point moves with precession, making it shorter than the sidereal year.

• Pope Gregory XIIIRelated: The Gregorian calendar more closely matches this seasonal year than the Julian calendar does.

• Calendar reformRelated: Its length sets the target for a calendar intended to keep seasons aligned.

• Hindu calendarRelated: Seasonal alignment depends on relating lunar months to the solar year.

• June solsticeRelated: Its relation to the equinoxes and solstices underlies the seasonal calendar.

• March equinoxRelated: It measures the seasonal cycle that the March equinox begins.

• PrecessionRelated: Equinox precession helps make the tropical year slightly shorter than Earth's orbital period relative to the stars.

• TropicsRelated: Its seasonal cycle governs the recurring solstices and equinoxes across the tropics.

• December solsticeRelated: Solstice-to-solstice intervals help define the seasonal year.

• September equinoxRelated: The equinox shifts against the civil calendar because a tropical year is not an integer number of days.

• Solar calendarRelated: Its length sets the seasonal cycle that a solar calendar must track.

• Winter solsticeRelated: The tropical year is measured from one seasonal point, such as a solstice, to the next.

• Christopher ClaviusRelated: The calendar’s seasonal alignment depends on approximating this year’s length.

• FebruaryRelated: Its length explains why a calendar needs occasional extra days.

• Spring (season)Related: The tropical year keeps seasonal dates aligned with the solar cycle.

• History of calendarsRelated: This seasonal cycle is the astronomical target for calendars intended to track seasons.

• Year (calendar)Related: The Gregorian year is designed to track this seasonal cycle.