Perihelion passage: Upon discovery perihelion was still 5 years away. An epoch of 2022 gives a more accurate perihelion date that properly accounts for planetary perturbations. An epoch 2017 unperturbed two-body solution (Sun+comet) gives a date of 2022-Dec-21. Integrating the orbit with JPL Horizons which accounts for planetary perturbations gives a date of 2022-Dec-19. The Minor Planet Center's Epoch Dec 2022 solution also gives a date of 2022 Dec. 19
Perihelion passage: Upon discovery perihelion was still 5 years away. An epoch of 2022 gives a more accurate perihelion date that properly accounts for planetary perturbations. An epoch 2017 unperturbed two-body solution (Sun+comet) gives a date of 2022-Dec-21. Integrating the orbit with JPL Horizons which accounts for planetary perturbations gives a date of 2022-Dec-19. The Minor Planet Center's Epoch Dec 2022 solution also gives a date of 2022 Dec. 19