A Golden Age of 10000 Years?

One reads in the Internet:

"In the Brahma-Vaivarta Purana, Lord Krishna tells Ganga Devi that a Golden Age will come in the Kali Yuga...Lord Krishna predicted that this Golden Age will start 5,000 years after the beginning of the Kali Yuga, and will last for 10,000 years."

This red marked sentence is not correct. The period of 10000 years mentioned in the Brahmavaivarta Purana started with the beginning of Kaliyuga (3102 B.C.) and will end in about 5000 years.

 ----------------------------------------
Brahmavaivarta Purāṇa 2.7:
----------------------------------------
Devanagari:  http://is1.mum.edu/vedicreserve//puranas/brahmavaivartapurana03.pdf  (page 19)

10. Having stayed in Kali for 5000 years on Bhārata, they abandoned the form of the river and went to the abode of Shrī Hari.
11. All the Tīrthas except Kāshī and Vṛindāvana will go together with them to Vaikuntha by the command of Hari.
12. At the end of 10.000 years of Kali Shālagrāma, the Mūrti of Hari, and the protector of the world left Bhārata and went to the abode of Hari.
13. The Vaishṇavas, the Purāṇas, the conches, the Shrāddha-tarpana, the actions prescribed by the Devas went together with them.
14. The Hari-pūjā, the name of Hari, the praise of the multitude of his glories, the Vedāngas, and the Shāstras went together with them.
15. Santa, Satya (truth), Dharma, the Vedas, and the village-Devatās, Vrata (vow), and fasting related to Tapas went with them also.
----------------------------------------
Brahmavaivarta Purāṇa 2.10:
----------------------------------------
Devanagari:  http://is1.mum.edu/vedicreserve//puranas/brahmavaivartapurana03.pdf  (page 42)

60. Gangā spoke: Lord!, if I go to Bhārata due the previous curse of Bhāratī (Sarasvatī) and now by your command and the Tapas of Rājendra (“Chief of kings”, Bhāgarathi),
61. How will the sins, which the sinners will give to me, be destroyed? Lord!, speak about that means.
62. Lord of All!, how long will I stay there on Bhārata and when will I go to the supreme abode of Vishṇu?
Shrī Kṛishṇa said:
...67. Lord of the Devas!, from now on you will stay for 5000 years of Kali on the earth in Bhārata due to the curse of Bhāratī (Sarasvatī).
...72. The sin of thousand sinners, which you receive from bathing, will be destroyed by the sight of my devotees.
73. What sin you receive through the touch of dead bodies of thousands of sinners, that will be destroyed from the bathing of those who worship me with my mantra.
----------------------------------------
Brahmavaivarta Purāṇa 4.34:
----------------------------------------
38. If an impure men reaches the Gangā and bathes with close connection, he is released from all sins, if he is not polluted again.
39. Her stay on Bhārata is for 5000 years in Kali. When she is present, Ah!, what is the strength of Kali? For 10.000 years in Kali my idols and the Purāṇas stay (on Bhārata), what strength of Kali is there?
----------------------------------------
Brahmavaivarta Purāṇa 4.90:
----------------------------------------
32. Shrī Kṛishṇa said:
For 10.000 years in Kali Hari stays on earth. The idol of the Devas is to be worshipped, the Shāstras and the Purāṇas.
33. For half of that time (5000 years), well fixed, the Tīrthas and Gangā etc. For (another) half of that time the village-Devas and the Vedas of the seers (stay on earth).
34. At the end of that time in Kali, Father!, unrighteousness is complete and the four castes will become one caste only.
----------------------------------------
Brahmavaivarta Purāṇa 4.128:
----------------------------------------
कलेर्दशसहस्राणि मदर्चा भुवि तिष्ठति ।
तदर्धानि च वर्षाणि गङ्गा भुवनपावनी ॥
kaler daśasahasrāṇi mad-arcā bhuvi tiṣṭhati |
tad-ardhāni ca varṣāṇi gaṅgā bhuvana-pāvanī ||28||

28. For 10.000 years of Kali my worship stays on earth. Half of the years of that time Gangā is purifying the earth.
----------------------------------------
Brahmavaivarta Purāṇa 4.129:
----------------------------------------
46-47. Gangā, Sarasvatī, Padmavatī and Yamunā, Godarī, Svarṇa-rekhā, Kāverī, Narmadā, O Muni, Sharāvatī, Bāhudā, Kṛitamālā, and Puṇyadā, they all went together to the highest Lord and bowed down.
48. The Devī Jāhnavī (Gangā) weeping, very sad with tears in her eyes, despairing with the grief of seperation, spoke to the highest Lord.
49. Bhāgarathī said: O Lord, O most excellent delighting one, you are going to the highest Goloka. What will happen to us in Kaliyuga?

श्रीभगवानुवाच
कलेः पञ्चसहस्राणि वर्षाणि तिष्ठ भूतले ।
पापानि पापिनो यानि तुभ्यं दास्यन्ति स्नानत ।। ५० ।।
śrībhagavānuvāca
kaleḥ pañcasahasrāṇi varṣāṇi tiṣṭha bhūtale |
pāpāni pāpino yāni tubhyaṁ dāsyanti snānata || 50 ||

मन्मन्त्रोपासकस्पर्शाद्भस्मीभूतानि तत्क्षणात् ।
भविष्यन्ति दर्शनाच्च स्नानादेव हि जाह्नवि ।। ५१ ।।
manmantropāsakasparśād bhasmībhūtāni tatkṣaṇāt |
bhaviṣyanti darśanācca snānādeva hi jāhnavi || 51 ||

50-51. Shrī Bhagavān said: Stay on earth for 5000 years of Kali. The sins, O Jāhnavī, which the sinners will deposit into you by bathing, will immediately be destroyed by the touch, sight and the bathing of those who worship me with my mantra.
52. Having gone to the place, where the names of Hari and the Purāṇas are, there you will listen attentively together with them ( Sarasvatī etc.).
53. By listening to the Purāṇas and by praising the names of Hari the sins arising from slaying a Brāhmaṇa etc. become destroyed.
54-55a. Also these sins become destroyed by the embracement of a Vaishṇava. As fire burns gras and dry wood, so the Vaishṇavas burn the sins of the sinners in the world.
55b-56a. The Tīrthas and the virtues which are on the earth, they are always in the purified bodies of my devotees.
56b-57a. By the dust of the feets of my devotees the earth becomes pure immediately.
Immediately the Tīrthas become pure and at once the world becomes pure.
57b-58. Those dear ones, who worship me with my mantra and eat what is left by me, and who always meditate on me, they are dearer to me than my life. By the touch of them wind and fire becomes pure.
59. For 10.000 years of Kali my worshippers are on earth. And when my worshippers have left they will have one caste only.
60-61. The earth void of my devotees will become seized by Kali. At this moment a four-armed being (Purusha) issued forth from the body of Kṛishṇa, shining like hundred moons, holding conch, Cakra, club and a lotus, being marked with the Shrī-vatsa.
62-63a. Having ascended a beautiful chariot he went to the ocean of milk. The daughter of the ocean spontanously became personified. The beautiful Lakshmī in bodily form was borne by the mind of Shrī Kṛishṇa.