Shabbat HaChodesh (“Sabbath [of the] month” שבת החודש) occurs either on the Shabbat before Rosh Chodesh Nisan or on Rosh Chodesh itself. The maftir reading is Exodus 12:1-20, which details eating the  Passover sacrifice, with “your loins girded, your sandals on your feet, and your staff in your hand”; eating bitter herbs and unleavened bread; and putting blood on the doorposts; and it lists the Passover laws. The first day of Nisan is also important as the occasion for God’s first commandment, sanctifying the new moon, which begins the Torah reading, “This month shall mark for you the beginning of the months; it shall be the first of the months of the year for you.” This commandment moved the determination of months from God’s agenda into the hands of the Jewish people–giving them control over time and the theological/liturgical cycle. The haftarah, Ezekiel 45:16-46:18, describes the sacrifices that the Israelites are to bring on the first of Nisan, on Passover, and on other festivals in the future Temple.