In their reference work, McClintock and Strong inform us that these offerings (especially those made on the first day of Unleavened Bread) were called hagigah (sometimes also transliterated chagigah), which means "festivity." These offerings were a festivity, something given in order to have a feast, a happy, festive time. If a person wanted to give God a peace offering, it was divided three ways: some to God, some to the priest, and the remainder came back to the offerer. With his portion, he would invite his family and friends, and they would have a fine time, eating a sumptuous meal and fellowshipping together.
These offerings are stipulated in Numbers 10:10. They are shown actually being offered in II Chronicles 30:22, included, in this case, under the name "Passover." But these offerings cannot be the actual Passover, because of the rules regarding the Passover having to be roasted and from a lamb or a kid of the goats. These offerings—the hagigah—are shown in II Chronicles 30 quite a number of times. This was when Hezekiah had his great Passover and Feast of Unleavened Bread in the second month.
John W. Ritenbaugh
The Night to be Much Observed