Visits from the Time Masters team or Rip Hunter (as an adult)....

Showcase #20: About 100,000,000 BC
Time Masters #2- #3 About 66,000,000 BC
Rip Hunter... Time Master #15: About 5,000,000 BC
Rip Hunter... Time Master #7 "1,000,000 BC" (probably around 14000 BC)
Rip Hunter... Time Master #25: "Dawn of Man"
Time Masters #8: About 50,000 BC
Time Masters #7: About 45,000 BC
Showcase #21: About 14,000 BC
Rip Hunter... Time Master #7: About 4000 BC
DC Comics Presents #37/2: 3709 BC
Rip Hunter... Time Master #7: About 3000 BC
Showcase #26: About 2000 BC
Time Masters #6: 2578 BC
Rip Hunter... Time Master #4: 1786 BC
Rip Hunter... Time Master #21: About 1200 BC
Rip Hunter... Time Master #9: 1000 BC
Rip Hunter... Time Master #10 1000 BC
Showcase #21: 700 BC
Rip Hunter... Time Master #2: 550 BC
Showcase #21: 331 BC
Rip Hunter... Time Master #11: 200 BC
Rip Hunter... Time Master #12: 100 BC
Rip Hunter... Time Master #1: 51 BC
Rip Hunter... Time Master #21: 31 BC
Rip Hunter... Time Master #6: August 25, 79 AD
Rip Hunter... Time Master #10 273 AD
Rip Hunter... Time Master #5: About 450 AD
Rip Hunter... Time Master #21: 579 AD
Rip Hunter... Time Master #8: 750 AD
Rip Hunter... Time Master #6: April 5, 798 AD
Rip Hunter... Time Master #3: 800 AD
Rip Hunter... Time Master #1: 950 AD
Showcase #25: 960 AD
Rip Hunter... Time Master #1 960 AD
Time Masters #5- #6: 980 AD
Rip Hunter... Time Master #22: 1194 AD
Rip Hunter... Time Master #13: 1280 AD
Rip Hunter... Time Master #1: 1360 AD
Rip Hunter... Time Master #17: July 8, 1360 AD
Legends of the DC Universe 80-Page Giant #1/7: 1492 AD
Rip Hunter... Time Master #14: 1502 AD
Rip Hunter... Time Master #16: 1560 AD
Rip Hunter... Time Master #16: summer 1573 AD
Rip Hunter... Time Master #24: 1580 AD
Rip Hunter... Time Master #26: February 13, 1633 AD
Rip Hunter... Time Masters #1: 1660 AD
Rip Hunter... Time Master #22: 1763 AD
Rip Hunter... Time Master #28: after 1765 AD
DC Comics Presents #77: after 1765 AD
Time Masters #4/Star Spangled Comics #69: 1770 AD
Rip Hunter... Time Master #23: before May 21 through October 19, 1781 AD
Rip Hunter... Time Master #21: About 1790 AD
Time Masters #3 (May 1990): September 16, 1874 AD
Rip Hunter... Time Master #20: summer 1944 AD
JSA #69- #72: October, 1951 AD
Suicide Squad Vol. 2 #10: 1959 AD
Booster Gold Vol. 2 #4 during Showcase #4
DC Comics Presents #37/2: Shortly before Justice League of America #144
Superman: The Legacy of Superman #1/5 travels to Superman #75
Booster Gold Vol. 2 #1: During World War III
Time Masters #8 2035 AD (possible future)
DC Comics Presents #78: (possible future of Chris KL-99, 22nd Century)
Rip Hunter... Time Master #12: 2162 AD (possible future)
Rip Hunter... Time Master #27: 2165 AD (possible future)
Booster Gold #13- #15 2462 AD (Booster Gold's future)
Rip Hunter... Time Master #14: 2550 AD (possible future)
Rip Hunter... Time Master #18: 2550 AD (possible future)
Valor #18-Valor #21: 30th Century (Glorith Timeline)
DC Comics Presents #37/2: 4784 AD (possible future)
Challengers of the Unknown #85- #87: About 12,000,000 AD (possible future)

-z