The great Sankirtan Movement of Lord Caitanya Mahaprabhu is a wonderful gift to the entire material universe, His appearance at the beginning of Kali-yuga, along with Kṛṣṇa's appearance at the end of Dvapara-yuga, is very, very rare as They both come to only one Kali-yuga and Dvapara-yuga out of every 1000, which is once every 8 billion 640 million human years.

Lord Caitanya Mahāprabhu comes "once" in a day of Lord Brahma. 

Lord Brahma lives for 100 years, which equals 311 trillion and 40 billion human years. 

So one day/night of Brahma is 8 billion 640 million human years.

Both Kṛṣṇa, as His original Vṛndāvana Form, and Lord Kṛṣṇa Caitanya Mahaprabhu only appear "once" during that vast amount of time.

As explained above, both Kṛṣṇa as His Vrndavana childhood Form, and Caitanya Mahāprabhu appear only "once" in Brahma's "day-time hours," which is 4 billion 320 million human years between sun-rise and sun-set.

Also, only in Brahma's "day-time" hours do the 1000 Maha-yugas exist, there are no Maha-yugas during Brahma's night.  

One Maha-yuga is made up of 4 yugas and their length of time is-

Satya-yuga - 1,728,000 human years.

Treta-yuga - 1,296,000 human years.

Dvarpara-yuga - 864,000 human years. 

Kali-yuga - 432,000 human years.

The total time span for "one" Maha-yuga is 4 million 320 thousand human years, and there are 1000 in Brahma's "day-time" hours.

When Krsna appears in the material world as His original Vṛndāvana Form, He appears at the end of just "one" Dvapara-yuga, out of the thousand that happen during Brahma's day-time hours.

And Caitanya Mahāprabhu appears just after Krsna appears at the end of Dvapara-yuga in the same Maha-yuga, near the beginning of Kali-yuga (almost 5000 years into Kali-yuga).

Lord Caitanya Mahāprabhu's rare appearance is just after Lord Krsna rare appears as His Vrndavana childhood Form at the end of Dvapara-yuga. Both come to this Earth planet "once" in a day of Brahma as explained above.

In Kṛṣṇa Lila (pastimes) when Radha and Krsna are combined as one spiritual Bodily Form, then that is Lord Caitanya Mahāprabhu. 

Many take it for granted without realizing how rare both Lord Krsna, as His original childhood Vrndavana Form, who appears at the end of a Dvapara-yuga, and Lord Caitanya's appearance, after Lord Krsna near the beginning of Kali-yuga (1486 A.D) [Christian calendar]

As explained above, Lord Kṛṣṇa as His original childhood Vrindavana Form, and Lord Caitanya Mahāprabhu, come only once in every ''day/night'' of Lord Brahmā during Brahma's day-time. 

Lord Caitanya appears in just "one Kali-yuga" out of every thousand Kali-yugas, and Kṛṣṇa as His childhood Vrindavana Form appears at the end of the Dvapara-yuga just before Caitanya Mahāprabhu appearance in the next Kali-yuga. 

This happens during Brahma's "day-time hours only" from sunrise to sunset. 

During the "night-time hours" from sunset to sunrise there are no Maha-yugas due to a partial annihilation that happens at night while Brahma sleeps.

This takes 4 billion 320 million human years, the length of Brahma's night time period, but also the length of Brahma's day-time as well.

As explained above, there are 4 yugas to a Maha-yuga or Catur-yuga. As said above, Lord Caitanya appears to one Kali-yuga out of every 1000 Kali-yugas with great His Sankirtan Movement.

And remember, Lord Krsna as His original Vṛndāvana childhood Form also only appears once at the end of a Dvapara-yuga, appearing in one Dvapara-yuga out of every 1000 just before Lord Caitanya Mahāprabhu's appearance near the beginning of Kali-yuga.

There are 4,320,000 human years in one maha-yuga (made up of 4 individual yugas), multiply that by 1000 and it will equal Brahma's 12 hour "day-time" period from sunrise to sunset, which is 4 billion 320 million human years long.

Then add another 4 billion 320 million years for Brahma's 12 hour night-time period (sunset to sunrise), when a partial annihilation, with no yugas, takes place and Brahma sleeps. 

Therefore the "day-time" hours and "night-time" hours together adds up to 8 billion 640 million human years which is a 24 hour "day and night time" of Lord Brahma.

A day/night also equals two Kalpas, one for daytime, one for nightime.

Therefore, we can understand that both Lord Krsna in His original Vrndavana Form, and Lord Caitanya Mahāprabhu's appearance, are very, very rare as they both only come once over that enormous period of time.

Keep in mind, modern mundane science foolishly claim the entire universe began 13.5 billion years ago from a speculative so called nonsense big bang theory. Their limited brain has almost no idea what's going on.

Yes, as emphasised above Krsna as His original Vṛndāvana Form comes "once" every 1000 Maha-yugas at the end of Dvapara-yuga, and Lord Caitanya Mahāprabhu comes "once" every 1000 Maha-yuga at the beginning of Kali-yuga, which all happen during the "day-time" period of Brahma, there are no Maha-yugas 

This also means there are 999 Kali-yugas that have no Lord Caitanya Mahāprabhu or His Golden Age of Sankirtan in it, this only happens to one Kali-yuga in a day of Brahma and 999 Dvapara-yugas where Kṛṣṇa as His original childhood Form does not appear. 

As also explained above, Brahma's night from "sunset to sunrise," is when a partial annihilation takes place and Brahma sleeps. This is also called the ‘Night of Brahma’ where their are no Maha-yugas during Brahma's night-time as explained above.

Also in the rare Kali-yuga Lord Caitanya Mahāprabhu appears in during Brahma's day-time, there is a 10,000 year Golden Age known as the Great Sankirtan Movement of Lord Caitanya Mahaprabhu, which is the congregational chanting of the Hare Krsna Maha-mantra in every Town, Village and City on the planet. 

In this very rare Kali-yuga, we are very fortunate to be given the great Sankirtan Movement of Lord Caitanya Mahaprabhu, and help spread the chanting of Hare Krsna all over the globe.

Over Lord Brahma's life of 311 trillion and 40 billion human years (100 of Brahma's years) Lord Kṛṣṇa and Lord Caitanya appear once in every day of Brahma which is 36,525 times over Brahma's life time.

So, how can we properly understand how the material world works? It seems we do not have the full Vedic explanation even though it does exist.

There is very strong evidence the world's continents (tectonic plates) are constantly on the move.

The constant movement of the continents around the world (tectonic plates) is a fact even though not mentioned in the Vedas we have.

The Vedic texts we have do not mention the movement of tectonic plates, instead, they only offer scriptural or divine explanations for earthquakes and movements, such as the activity of subterranean serpents (nagas) or the actions of demigods and demons. 

The Vedas focus on ancient cosmology and religious rituals rather than modern scientific understanding of geology and the constant movement of continents (tectonic plates) which ia also be true and proven even though not mentioned in the Vedas. 

Vedic explanation of Earth movements over material time - Earthquakes are attributed to the movements of the demigods and creatures like the nagas or the actions of other divine beings.

Earthquakes are seen as punishment from the demi-gods and is a means to cleanse the earth of negative energy.

Cosmology - The Vedas contain texts about the origin of the material universe, including concepts of a spherical earth (Bhurloka) and its place within a cosmic system (14 planetary systems). 

Is there a modern scientific framework that agrees with the Vedas? 

While early Vedic scholars attempted to understand natural phenomena of this material world, Vedic explanations for earthquakes are based on scriptures like the Srimad-Bhagavatam and Maha Bharata and caused by the demigods and the collective karmic pious and impious reactions of humans. 

This fact does not align with the modern scientific limited understanding of the movement of the ground and the continents (tectonic plates).

However, that does not mean the movement of continents (tectonic plates) is not happening.

The movement of tectonic plates is also a proven fact supported by satellite measurements, geological evidence like matching coastlines and mountain ranges, fossil and rock correlations, the distribution of earthquakes and volcanoes along plate boundaries, and the evidence of seafloor spreading, which shows new crust being formed and old crust being consumed. 

Advanced satellite technology (like GPS) allows scientists to directly measure the precise movement of landmasses on both sides of plate boundaries. 

Earthquakes and volcanic activity are predominantly concentrated along plate boundaries, indicating interaction between the moving plates. 

The coastlines of continents, such as South America and Africa, fit together like puzzle pieces, suggesting they were once joined. Also the Australian continent will over millions of years join with India, the Australian continent moves north at about 7 cm per year.

Identical rock formations and mountain ranges, like the Appalachians in North America and the Scottish Highlands, are found on different continents, indicating a shared geological past. 

Glacial striations (scratches left by glaciers) and coal deposits in present-day tropical regions demonstrate that continents were once in different climatic zones, supporting their past movement. 

The discovery of identical or similar fossils of plants and animals on widely separated continents provides strong evidence for continental drift. For example, the Mesosaurus reptile fossils found in South America and Africa could not have swum the vast Atlantic, implying the continents were once connected.

Sampling the ocean floor revealed that new oceanic crust is continuously being formed at mid-ocean ridges and old crust is being pushed away, a process only explained by moving tectonic plates.

The pattern of magnetic anomalies on the seafloor also provides evidence of seafloor spreading, showing the symmetrical movement of plates away from mid-ocean ridges.

All glories to Lord Kṛṣṇa Caitanya Mahaprabhu.