Studying these events, it is somewhat amazing how they tie together. Old and New.
The Passover (first) Lamb was brought to the home on the 10th day of the first month. (Individual households)
The Day of Atonement (Made in the Sanctuary, Holy Place) was on the 10th day of the 7th month. (Sins for all the people)
The first lambs were killed on the 14th day of the first month, at twilight, right before the 15th day started. (Sins washed, blood on door posts)
The Feast of Unleavened Bread started on the 15th day of the first month. (Sins washed, Leven out)
The Feast of Tabernacles (Ingathering) started on the 15th day of the 7th month, right after the Day of Atonement. (Atonement Made-Sins out, Christ born during this time, we tabernacle with Him, spiritually gathered)
And as we all know the time of the Cross coincides with the first Passover which collected all the feasts and put them in Him. (Passover Lamb- Atonement made, our bread of life-Leven out, Gathered-Our new tabernacle-home, In Him)