Wan time exist outside of matter? Will time exist after the kingdom of God arrives?
The Kingdom of God
Jesus spoke often about the kingdom of God, so what exactly is the kingdom of God? Is it heaven? Is it Paradise? Is it the Church? Is it the New Jerusalem (Rev 21:1-4)? Jesus must have thought it was important because He mentioned the kingdom of God or “the kingdom” at least 126 times! The Kingdom of God is the same thing as the Kingdom of Heaven, and this “kingdom” talk has been around for a very long time. The psalmist wrote that, “The Lord has established his throne in the heavens, and his kingdom rules over all” (Psalm 103:19). Jesus told the disciples (and us) to pray for the “kingdom to come” (Matt 6:10), so we know it’s something Christ desires to come, and we should too. Since Jesus wanted us to pray for the kingdom to come, it was apparent that the kingdom had not yet come in its fullness. The Jews didn’t even realize that with Jesus there, “the kingdom of God is in the midst of you” (Luke 17:21), and the King of that coming kingdom said, “If it is by the finger of God that I cast out demons, then the kingdom of God has come upon you” (Luke 11:20). The kingdom of God was near because the King of that kingdom was with them, but of course, they rejected Jesus and the gospel of the kingdom of God, however, that rejection would not stop the kingdom from coming because it is the kingdom of God, and who can stay the hand of God? 
The Bible shows us that in the beginning, there was only God and nothing else (John1:1-3), but to give us a reference point, it says, “In the beginning, God created the heavens and the earth” (Gen 1:1), so the questions are, “Can time exist without matter? Did time even exist before creation?” I don’t see how time can exist without matter because it is matter by which we measure time, so again, “Can time exist without matter?” Albert Einstein said “No” but Sir Isaac Newton believes time can exist without matter, believing that time is absolute. He wrote that time flows equably without relation to anything external, however Einstein would disagree because time is relative and depends on the mass and speed of matter, and so for him, time is only a result of physical processes of moving mass or moving particles, and without matter and movement, you could not have a scale by which to measure time. Solomon wrote, “For everything there is a season, and a time for every matter under heaven: a time to be born, and a time to die; a time to plant, and a time to pluck up what is planted; a time to kill, and a time to heal; a time to break down, and a time to build up” (Eccl 3:1-3), but what happens to time in eternity or when Jesus comes to establish the kingdom of heaven?
Time Shall Be No More
When the New Jerusalem comes down out of heaven (Rev 21:1-4), it says that “the city has no need of sun or moon to shine on it, for the glory of God gives it light, and its lamp is the Lamb” (Rev 21:23), so “night will be no more. They will need no light of lamp or sun, for the Lord God will be their light, and they will reign forever and ever” (Rev 22:5). If the glory of the Son of God overwhelms the sun itself, and He will, and if the sun and moon will cease to exist, will time exist because we use the sun to gage time? Doesn’t there have to be a sun in the sky to know what time it is? Will time really matter in eternity since we’ll have all the time in the world? Time may exist in the kingdom, but what about schedules? Do we need to set the clock or the alarm in the kingdom? We’ll have new bodies and have no need for sleep, but what about those still living after the kingdom arrives? Will time matter to them? Will time matter to us who have glorified bodies? Time will not be a problem and I don’t believe we’ll have to “save time” or “make time” or “run out of time,” because in the kingdom, we’ll have all the time we’ll ever need.
Sometimes the kingdom of God and the kingdom of heaven are used interchangeably, and that’s because they are basically the same thing, but time will probably exist after Jesus’ sets up His kingdom with the New Jerusalem. Otherwise, how will those who are still alive on the earth reckon time since the sun and moon will be no more? Perhaps the Bible isn’t saying the sun and the moon will cease to exist, but that we may not be able to see the sun or the moon because of the glory that emulates from the Son of God, Jesus Christ. His glory will surpass that of the sun, the moon, and the stars, and so much so that they might not even be visible, so will time exist in the kingdom of God? I believe it will, because there will be matter, and there will be times to come and worship the King of kings and Lord of lords on certain prescribed days. We don’t know for sure if time will be relevant, but it seems that time will exist because matter will exist, and that’s our reference point for time (remember Einstein’s comment in paragraph two). Time may exist, but it won’t be a problem for believers because you see, we’ll have all the time in the world…and we’ll abide with Christ for all time…and that means we’ll have time without end.
Here is some related reading for you: What is the Kingdom of God or Kingdom of Heaven? A Bible Study 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible: English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.