Charles Ellicott Commentary 2 Chronicles 35:16

"So all the service of Jehovah was prepared the same day, to keep the passover, and to offer burnt-offerings upon the altar of Jehovah, according to the commandment of king Josiah." — 2 Chronicles 35:16 (ASV)

The same day. —On that day, that is, “at that time” (2 Chronicles 35:17).

To offer burnt offerings. —To burn the fat of the Passover victims, and of the peace offerings. The verse summarizes the preceding account (Compare 2 Chronicles 35:10).