There are 365.2422 days between spring equinoxes, 365.259636 days between Earth's perihelions, and 365.25 days in a light-year.

Three figures, judged against standard astronomical values. (1) Days between spring equinoxes: the mean tropical year is about 365.2422 days (the vernal-equinox year is about 365.2424). Either value counts as correct to the stated precision. (2) Days between perihelia: the anomalistic year is about 365.259636 days. (3) The light-year is defined using the Julian year of exactly 365.25 days. Read the light-year part as a joke about this definition; it counts as correct if the light-year is defined with 365.25-day years. True: all three match. Mostly true: all three are essentially correct, but one differs in the last digits in a way that matters only at the claim's stated precision (e.g. the vernal-equinox interval is really 365.2424). Mixed: one of the three is clearly wrong. Mostly false: two are wrong. False: all three are wrong, or the light-year is not defined using a 365.25-day year and the other figures are also wrong.

Set before the research began.

1. E1 A role for orbital eccentricity in Earth's seasonal climate - Geoscience Letters Springer (Geoscience Letters) · 8 December 2023

   “The anomalistic year is based on the period between successive perihelia, currently 365.259636 days (United States Nautical Almanac Office, 2019). The tropical year is based on the period between successive equinoxes (365.242189 days)”

2. E2 Leap Years U.S. Naval Observatory (aa.usno.navy.mil) · 1 January 2000

   “known as the tropical year, is approximately 365.2422 days.”

3. E3 The Galileo Project | Chronology The Galileo Project (Rice University) · 1 January 1995

   “The mean interval between successive vernal equinoxes (365.2424 days), is about 11 minutes less than 365 1/4 days;”

4. E4 A role for orbital eccentricity in Earth's seasonal climate - Geoscience Letters Springer (Geoscience Letters) · 8 December 2023

   “The anomalistic year is based on the period between successive perihelia, currently 365.259636 days (United States Nautical Almanac Office, 2019).”

5. E5 A role for orbital eccentricity in Earth's seasonal climate - Geoscience Letters Springer (Geoscience Letters) · 8 December 2023

   “The tropical year is based on the period between successive equinoxes (365.242189 days) and is also the year that the Gregorian calendar is based on”

6. E6 The Galileo Project | Chronology The Galileo Project, Rice University · 1 January 1995

   “The mean interval between successive vernal equinoxes (365.2424 days), is about 11 minutes less than 365 1/4 days;”

7. E7 Astrodynamic Parameters NASA Jet Propulsion Laboratory (Solar System Dynamics) · 1 January 2000

   “Julian year | y | 365.25 d | 1. (see below) |”

8. E8 Year - Wikipedia Wikipedia · 25 October 2001

   “The mean tropical year is approximately 365 days, 5 hours, 48 minutes, 45 seconds, using the modern definition[15] (= 365.2421875 d × 86400 s = 31556925 s).”

9. E9 Year - Wikipedia Wikipedia · 25 October 2001

   “| 365.259636 | Anomalistic, averaged and then rounded for epoch J2011.0 |”

10. E10 Light-year - Wikipedia Wikipedia · 19 September 2001

    “As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (365.25 days).[2]”

The U.S. Naval Observatory gives the tropical year as about 365.2422 days [E2], and a peer-reviewed paper gives the interval between equinoxes as 365.242189 days [E5]. The 365.242189 figure rounds to the claim's 365.2422, which the criteria accept as the mean tropical year. The anomalistic year, the time between successive perihelia, is given as 365.259636 days in [E4], which cites the United States Nautical Almanac Office (2019), and the same figure appears in [E9]. The IAU defines the light-year using the Julian year of 365.25 days [E10], and NASA JPL also lists the Julian year as 365.25 days [E7], so all three figures match.