from webgeocalc DistanceFinder Aphelion of 2023: 2023-07-06 20:06:38.435260 UTC similarly, periphelion of 2023: 2023-01-04 16:17:27.532134 UTC IMCCE: slowest orbital speed is on aphelion? de-mythstified: According to Kepler's laws , AMS >> Yes. But by observation >> Sort of: 10 July in 2023(sqrt(dx^2+dy^2)): IERS dx: dy: 60135 is modified Julian date, Keisan Solar Distance can be found by JPL SSD , reading AD (Apoapsis distance) column, time is in TDB Reference: IMCCE perihelion 2023 IMCCE aphelion 2023 earthscience stackexchange and python script( less than 15 sec of deviation) Jay Tanner PHP GSFC Earth fact sheet Better than 1 minute resolution , UTC2TDB online convertor