Problem: According to this verse the fast associated with the Day of Atonement was to begin on the “ninth day of the month.” But earlier in Leviticus 16:29 they were to begin fasting on the “tenth day of the month.”
Solution: This fast began on the ninth day and extended over to the tenth day (cf. Lev. 23:27). Hence, it was appropriate to speak of it as being either day. There are several other problems of a similar nature. For example, in like manner the feast was both seven days (Ex. 12:15) or six days (Deut. 16:8). God ended His work of creation on the seventh day (Gen. 2:2) and yet did it in six days (Ex. 20:11). Also, “after eight days” means the next Sunday (John 20:26; cf. 20:19).