God made time, God can change time.
1) The creation week was a liturgical, creational calendar that celebrated God the Maker and Sustainer. Creation’s calendar said, “Six days of work then one day of rest.” It was patterned after God the creator’s “week.”
2) The exodus event was a real sort of de-creation then re-creation (see Fretheim and Enns, for example). Among other things, the calendar was “tweaked.” There was a new first month: Abib (Ex 12.18, 13.4, etc.). A huge redemptive event, a new creation of sorts, meant that Yahweh would “tweak” the creational calendar. Now the Hebrews had their own unique calendar based on God’s re-creative work which was patterned into their very existence. In other words, God stretched the creational calendar at the exodus.
3) The OT exodus event pointed to the NT exodus fulfillment: God’s eternal, “firstborn” Son, the true Israel, the true Passover Lamb, the true Bread of Heaven, etc. came to keep and complete (fulfill) all the OT signs, symbols, sacraments, ceremonies, and calendars. His death meant blood covering God’s people, it meant justice was paid and people were released. It meant a new creation – Jesus is the firstborn from the dead (Rev 1; cf Col 1). No surprise: Jesus re-arranges the calendar that he made, tweaked, and now fulfilled. The “newly created” people of God (the church) meet on the first day of the week (cf. Acts), the great day that Jesus set apart by defeating death and began making all things new. This first day is patterned into the existence of the church. The Creed says it too: “the first day he arose again from the dead.” Everything is new: death is whipped, the new has come, and a new calendar and liturgy reflect this truth. God is not only the Maker and Sustainer, but the Redeemer as well. The Christian calendar is the liturgical way to say as much.
4) Finally, this New Exodus-Christian calendar begs for the end of itself: patterned into the Christian calendar is the end. Every first day preaches that there will be a last day: Come, Lord Jesus, come quickly! On heaven’s calendar, each “day” is the great new Sabbath because of the completed work redemption. The calendar we now have between Jesus’ “exodus” (his resurrection/ascension) and our “exodus” (his parousia) is a New Exodus Pilgrim calendar that we won’t need after this age.
God made time, God can change time!
Note: this was pieced together from the above commentaries/books (namely, the IVP OT Background Commentary, Enns, Exodus, Fretheim, Exodus, and several of Kline’s works, including God, Heaven, and Har Magedon) along with the Westminster Confession of Faith 21.7 and the Dictionary of Biblical Imagery.