The year 207̃012 was the date the triangulums first contacted Earth, opening a time portal and traveling through. While arriving with the intention of creating a peace treaty with the humans, (being already familiar with the species), they were immediately accosted by a giant Time Baby. The Time Baby attempted to shoot them down with its eye lazers, injuring the portal's operator and shutting it down.
Stuck in the current dimension, party leader Bill Cipher came up with the idea to escape their pursuer using the city's pneumatic tubes. However, due to a malfunction in the system, they ended up in the ruined Aperture Science facility. The vast amount of time it took for them to reach the surface allowed the operator to heal, and fortunately shielded the group from the attacking Alternian invasion fleet. The human race, unfortunately, suffered huge blows, and by the time the triangulums finally contacted them, very few humans were left.
A deal was struck, the humans were granted immortality and time travel devices in exchange for their assistance with maintaining the dimension's time flow. Lead by the Time Baby, no longer raging, the newly formed Time Paradox Avoidance Enforcement Squadron managed to beat back the invading trolls, with a last-minute sabotage plan, carried out by a blackmailed Blendin Blandin being narowly averted by officers Dundgren and Lolph. In punishment, Blendin was sent back in time to fix a major time anomaly. After celebrating the victory, the triangulum operater opened a time portal into the beginning of humanity, thereupon signing the treaty with earlier humans.