The Feasts of Trumpets  is the 5th of 7 Feasts of the Lord per Lev.23 and continues to outline the Foundation of Prophecy and Eschatology Hermeneutics which include the Typology and prophecy fulfilled by the 1^st 4 Feasts of Passover, Unleavened Bread, First Fruits aka Easter, and Feast of Weeks aka Pentecost, thus setting the stage for 2 of the last 3 Feasts of Trumpets and Feast of Atonement to culminating with the "Year of Jubilee" aka the "Millennial Kingdom"; to complete all prophecy related to the "End of the Age" (End of THIS Age), with the Feast of Tabernacles fulfillment of prophecy completed much latter after the Millennial Kingdom, the release of Satan, a second "Gog and Magog" battle and the "Great White Throne Judgment" for fulfillment of the next (3rd), and last Age. 

The Etymology of the Hebrew word translated "Feasts” means Solemn Appointed Times; such as the fulfilled prophecies and typologies related to the first 4 Appointed TIMES with God during the Feasts of Passover, Unleavened Bread, First Fruits aka Easter, and the Feast of Weeks aka Pentecost at Jesus' first coming.

Jesus Parousia also relates to the next 2 Feasts of Trumpets and Atonement and Tabernacles.  The Feasts of Trumpets and Atonement describe a time of “tribulation”; exemplified by the first six seals of Rev. 6 and by Jesus in Mth. 5 - 31; followed by the Day of the Lord and His Wrath, the Apocalypse and Armageddon: occurring between the Feast of Trumpets unto the Feast of Atonement at the period called the10-day / years “Days of Awe” aka a period of Repentance, finalized at the Year of Jubilee, aka the Millennial Kingdom, aka Marriage Supper of the Lamb.  All made available by His Redeeming Grace and Call to Holiness outlined by these 7 Feasts of the Lord per Lev. 23; God's Calendar of Redeeming Grace!   

Feast of Trumpets to Feast of Atonement to Year of Jubilee overview:

The Feast of Trumpets is the fifth of seven feasts of the Lord aka 'appointed times' in God's calendar of redemption for mankind.  As Jesus has fulfilled the first 4 feasts at His First Coming, the Second Coming starts with the Feast of Trumpets; followed by the Feast of Atonement, culminated by the Year of Jubilee.  Basically, the Feast of Trumpets initiates a call to repentance which starts on the 1st day of the 7th biblical month.  It continues for the next 10 days until the Feast of Atonement aka Judgment on the 10th day of Tishri and Jubilee on the 11^th day.

God states:  "I have appointed to you each day as a year",   Ezek. 4:6b.  See also: Dan. 7:25, 12:9 and Rev. 11:2-3,  12:6, 13:5.

God states in Ezekiel 4:6b and Revelation 2:8-11 that He has appointed each day unto mankind as 1 year, in prophetic terms.  It has been proven to be thus in Daniel 9:24-25, the prophecy of the 69 periods of 7 or 173,880 days / years at Jesus' First Coming. 

The Feast of Atonement on the 10th day is followed immediately by the year of Jubilee aka Millennial Kingdom on the 11th day of Tishri.  Here this one day is changed to represent 1,000 years, based upon different Scripture stating that "each day with the Lord is as 1000 years", i.e. Millennial Kingdom (2 Peter 3:8).

It's also noteworthy to observe that Jesus ascended on the 40th day after His Resurrection, 10 days prior to the Feast of Pentecost.  Jesus completes this 10-day period from the Feast of Trumpets to the Feast of Atonement, culminating with the Year of Jubilee, which is comprised of 50 years.  Essentially Pentecost is a typological foreshadowing of the Year of Jubilee at Jesus' Second Coming. 

A phrase was coined from Rev. 3:5 which states "May your name be written in the Book of Life".  This is a typical salutation given between the Jews during this period of repentance.  In other words, repent and get your life right with God prior to judgment, or not be written in the Book of Life for an eternity with the Lord.

"He that overcometh, the same shall be clothed in white raiment; and I will not blot out his name out of the book of life, but I will confess his name before my Father, and before his angels."  Rev 3:5

See “Feast of Trumpets to the Feast of Atonement to Jubilee” at:

http://www.feastsofthelord.net/feasttrumpets/id19.html  

As God stated in Ezekiel 4:6b that He has appointed each day unto mankind as 1 year in prophetic terms.  It has been proven to be thus in Daniel 9:24-25, the prophecy of the 69 periods of 7 or 173,880 days / years at Jesus' First Coming.  Revelation 2:10b also states that there will be tribulation for 10 days:  "and ye shall have tribulation ten days: be thou faithful unto death, and I will give thee a crown of life".

YOU SHALL HAVE  TRIBULATION 10 DAYS - Rev. 2:8-11   "HE THAT OVERCOMES SHALL NOT BE HURT BY THE SECOND DEATH" –  REPENT

The Feast of Atonement on the 10th day is followed immediately by the year of Jubilee aka Millennial Kingdom on the 11th day of Tishri.  Here, this one day is changed to represent 1,000 years, based upon: "each day with the Lord is as 1000 years", i.e. Millennial Kingdom (2 Peter 3:8).

The Year of Jubilee on the 11th day of Tishri represents 1000 years.  This includes satan's being locked up, then released at the end of the 1000-year reign.  Then another Gog-Magog battle occurs followed by the Great White Throne Judgment and the Feast of Tabernacles described in Rev. 21 & 22.  The Feast of Tabernacles is on the 15th day and represents an eternity with God.

Scripture seems to clearly state that there's an age beyond the end of this age initiated by the 1000-year reign of Christ.  After this, satan is released until finally eliminated at the Great White Throne judgment.  Given there are 4 days between the Year of Jubilee and the Feast of Tabernacles, it would seem that this may also represent an additional possible time period of some 4000 years which may or may not be the circumstance.  Given that the earth had been completely destroyed except for the 144,000, it will take a considerable period of time before the population may be large enough to actually effectuate another Gog-Magog battle.  In any case, there is an age, a substantial period of time following the Feast of Atonement aka Judgment and the year of Jubilee aka Millennial Kingdom until the Feast of Tabernacles.