20 You are to do the same on the seventh day of the month for anyone who sins unintentionally or through ignorance; so you are to make atonement for the temple.

Read Ezekiel 45:20 Using Other Translations

And so thou shalt do the seventh day of the month for every one that erreth, and for him that is simple: so shall ye reconcile the house.
You shall do the same on the seventh day of the month for anyone who has sinned through error or ignorance; so you shall make atonement for the temple.
Do this also on the seventh day of the new year for anyone who has sinned through error or ignorance. In this way, you will purify the Temple.