The date of Khufu/Cheops and/or Great Pyramid and/or Sphinx and/or 4th dynasty has ranged from 150,000 yrs ago (some believe), 73,300 yrs ago (Balkhi), 10,000 bc (Pyramidology), 7000-5000 bc (Sphinx, Schoch), to 4731 (Petrie) to 3733-3600 (Bey) to 2900-2750 (Breasted, Berlin school) to 2690 (LA Times in 1990s) to 27th cent bc / 2613-2498/2494 (Clayton, Shaw, recent conventional consensus in 2000 ad) to 2144/2140 bc, to 1726-1703/1699/1663 (Hoeh), to 838 bc (Newton), [to not before 800 ad (Fomenko)?]
There is an admitted amount of uncertainty in 4th dynasty dates in orthodox Egyptology as seen by these quotes: "The boat of Khufu dates 200 years before Egyptological date of pyramids built." "Kate Spence's astronomical work says Khufu's pyramid should be dated 50 years the other way from the historical date ... in other words 250 years lower than the radiocarbon date."
More evidence of uncertainty of 4th dynasty dates is seen by the different regnal years in different sources, eg: Cheops/Khufu's reign length ranges from 63 yrs (Manetho) to 50 yrs (Herodotus) to "46 yrs" (one modern orthodox theory of cattle-count?) to 34 yrs (Great Pyramid inscription biennial cattle-count) to 26/27 yrs (Dakhla inscription bienniel cattle-count) to 24/23 yrs (Turin King List) to 20 yrs (building pyr Herodotus) to 17 yrs (Great Pyramid inscription taken verbatim) to 14 yrs (Dakhla inscription taken verbatim) to 10 yrs (building pyr ramp Herodotus). Chephren/Khafres reign length range is 66 yrs (Manetho) to 56 yrs (Herodotus) to 26 yrs (Clayton) to 24 yrs (Turin and inscription near tomb of Nekure). Mycerinus/Menkaure's reign length range is 63 yrs (Manetho) to 44 yrs (Herodotus) to c 28 yrs (orthodox Egyptologists) to 12 yrs (Herodotus)? to 6/7 yrs (Herodotus)?
A discovery of ours that majorly bears on the date of the 4th dynasty is that there is alot of evidence for that Joseph was in Egypt in the 2nd/3rd to 4th/5th dynasty, and further that Jacob pretty certainly matches Cheops/Khufu of the 4th dynasty. (See chapter 3 on dynasty 3 for important initial information on Joseph not given in this chapter.) Goshen where Jacob dwelt when he was in Egypt seems from various evidences to match Giza/Gizeh/Er-ges-her "beside the high". Herodotus said shepherd Philitis "lover of righteousness" dwelt at Giza in the 4th dynasty, and this Philitis is very similar to Jacob.
The name Khufu/Khufwey/Cheops is similar to the name Jacob. Both names have same/similar 2 or 3 consonants. Either the Egyptian name is only a 2 consonant abbreviation, or it is same 3 consonants except that the j/y seems reversed/transposed in the Egyptian name. If the syllable is transposed then either there is a genuine change or it is a false appearance and the "Khufu" name is not correct modern transliteration. There are a number of seeming cases of similar "reversal" of elements between Biblical & Egyptian names including Potiphera & Ra-hotep? Khufwey & Jacob, etc. Many names in Egyptian king lists etc have had disputed correct order of name elements eg Re-djedef or Djedef-re, Ni-user-re or User-en-re, etc. Hieroglyphic inscriptions are not written in single straight lines but in 2 dimensional patterns, and so they might possibly be read any number of possible ways, and the believed "rules" of direction/order might be wrong. The name Kh-u-f-u / Kh-u-f-wey / H-wj=f-w(j) itself is written in way that might be read in different ways (in photo it is bird top left, disk (kh) top right, snake (f) in middle, bird bottom, all pointing right, which Bey draws with disk on left and bird on right and all pointing left, while in Clayton's drawing it is disk top left, snake bottom left-middle, bird top middle, bird right all pointing left). Directions of reading/writing may have also changed in history (perhaps like the sun changed directions a few times in history according to some texts), and/or different nations read in different directions (some left to right, some right to left, some read books front to back, some read books back to front, and some read top to bottom or bottom to top?) Also, if names have been read either Akhenaten or Khunaton, Akhet or Khut, then possibly Khufwey could also be read Akhuf?
Jacob(-el)'s name can mean "may El/God protect" (compare Yaqub-har "god Har watches over"). (Khnum-)Khufu's name is said to mean "protected (by Khnum)". (Khnum is a creator god similar to El/Yah. Khufu & Khnum-Khufu might match Jacob & "mighty one of Jacob"?) Jacob was in Egypt for 17 yrs. Khufu's highest reign length in contemporary inscriptions is 17 yrs. (All the other reign lengths are from later non-contemporary less-reliable sources except for the 2 inscriptions.) Jacob had 2 or 3 or 4 wives. Khufu had 2 or 3 or 4 wives. There are 3 satellite pyramids beside the great pyramid which some say are of Khufu's wives/queens. (Rachel died before Jacob went to Egypt.) Jacob had 4 + 2 (+ 2) & 2/3/4 (+ 2) sons = 12/13/14 sons. From various sources Khufu seems to have had between 6 to 9 to 15 sons. There is also a similar number of tombs/mastabas on 1 or 2 sides of the great pyramid? Jacob adopted Joseph's 2 sons Ephraim & Manasseh. At Giza there are 3 pyramids of Khufu, Khafre, Menkaure. Khafre is called Suphis 2 in some sources which may match Ephraim as Jacob's The many mastabas/tombs on one side of the Great Pyramid might be of the 70 souls that came with Jacob into Egypt and/or the Israelites. (The aerial-view-from-above pictures look/feel to me like they are Israelites around/by Jacob's pyramid.)
Table/list: Khufu/Cheops = Jacob? shepherd Philitis "lover of righteousness" = Jacob? Djedef-re = Joseph or Judah? Sphinx/Sheshep-ankh (Hu) ="head of Joseph" (Zaphenath-paneah) & lion of Judah (Gen 49)? Khafre/Chephren = Ephraim? Menkaure/Mycerinus = Manasseh? Pyramids = "eternal mountains" (Gen 49)? Giza/Ergesher = Goshen?
In orthodox chronology the Akkadian dynasty of Mesopotamian history has synchronism with the (4th-)6th dynasty of Egypt. The Akkadian dynasty might be connected with Joseph's sons and the 4th dynasty of Egypt because Manishtusu succeeded his younger brother similar to the younder brother Ephraim was put before the elder brother Manasseh when Jacob blessed Joseph's sons. (One source on Manishtusu says "... speculation ... that the two were twins, as in: man istusu? rimus! "Who is with him? His beloved!", as apparently the second born was thought to be the first conceived.") The bust of Manishtusu does possibly look similar to the statue of Menkaure/Mycerinus.
Dating the 4th dynasty by astronomical (stars) synchronisms is problematic because ancient sources say that there have been changes in the movements of the earth and other bodies in ancient times and thus altered alignments and orientations. There are also differences in claimed astronomical dates eg the pyramids supposed to mirror Orion's belt in 10000 bc, Sphinx supposed to face Leo in 10750/10500/10006-8600/8006/8000 bc, Great Pyramid shafts align with stars in 2000s bc. It is possible that the Egyptians did have stars dating and that there might be some star date found in future like for example the name of Djedefre's pyramid "Djedefre's starry sky" might possibly have a connection with stars alignments.
Examples of recorded changes in movements of earth & celestial bodies: Sarah's pregnancy was for a 10 months "year". 3 Stonehenges (ref Velikovsky)? Joshua's long day. Long night "without dawn for 20 hours" in Peruvian. The longest & shortest days in Egyptian match present Sudan. Hyksos king altered calendar. Egyptians had 5 added days week/month to the year. Venus tablets of Ammi-saduga. Barak's "stars fought in their courses" (Judges). Orion going in opposite direction in Egyptian painting. Phaethon "change in path of sun" in Atlantis Account (Flem-Ath). Hezekiah's sun go back 10 steps. Hebrew prophecy has 360 days year. Numa added 2 months to calendar. Mayans had 360 days year and adding 5 days to make a 365 days year. Herodotus said Egyptians said sun changed directions 2 x 2 times.
The 3 pyramids of Sipan in the Andes region look somewhat analogous to the 3 pyramids of Giza. This might be another indication of a lower date than the orthodox-held date for the 4th dynasty.