Events by day
- April 1st
- April Fools' Day. (TNG: "Brothers")
- April 4th
- In 2063, the USS Enterprise-E, in pursuit of a Borg sphere, arrives in the past from 2373. (Star Trek: First Contact)
- April 5th
- In 2063, Zefram Cochrane launches the Phoenix and subsequent First Contact with the Vulcans occurs. (ENT: "Regeneration"; Star Trek: First Contact; VOY: "Year of Hell")
- In 2378, the USS Voyager crew celebrates First Contact Day. (VOY: "Homestead")
- In 2385, rogue synthetics launch an attack on Mars, destroying the Utopia Planitia Fleet Yards and setting the planet ablaze. (ST: "Children of Mars", PIC: "Remembrance", "Maps and Legends")
- April 9th
- Jonathan Archer is transported back in time from March of 2152 by Daniels, who reveals that the Cabal, and not Enterprise NX-01, was responsible for the destruction of a colony on Paraagan II. (ENT: "Shockwave")
- In 2342, Jean-Luc Picard arranges to meet Jenice Manheim at the Café des Artistes in Paris, but never shows. (TNG: "We'll Always Have Paris")
- April 16th
- In 2151, Enterprise NX-01 is launched. (ENT: "Broken Bow", "The Andorian Incident")
- In 2152, Jonathan Archer, Charles Tucker III, and T'Pol discuss T'Mir and her early contact with Humanity. (ENT: "Carbon Creek")
- April 22nd
- In 2375, Ancestors' Eve is celebrated aboard Voyager. (VOY: "11:59")
- April 24th
- In 1987, Gabriel Bell is born on Earth. (DS9: "Little Green Men")
- In 2153, Enterprise NX-01 arrives back at Earth for a refit after the Xindi attack on Earth in March. The IKS Bortas, commanded by Duras, is chased off by three Starfleet ships, after pursuing Enterprise to Earth from Klingon space. (ENT: "The Expanse")
- April 30th
- in 2236, May Ahearn is born in San Francisco, California. (DIS: "New Eden")
In 1968, the United States of America launches an orbital nuclear weapons platform from McKinley Rocket Base, causing an international crisis. The USS Enterprise travels back in time from 2268 to study history and becomes involved in the platform crisis. (TOS: "Assignment: Earth")
In early April of 2151, a K'toch-class scout ship piloted by the Klingon courier Klaang crash-lands in Broken Bow, Oklahoma, initiating the Broken Bow Incident and resulting in first contact between Earth and the Klingon Empire. (ENT: "Broken Bow")
|Months of the year|
|Earth months: January • February • March • April • May • June • July • August • September • October • November • December|
|Qo'noS months: Maktag • nay'Poq|
|Vulcan months: Tasmeen|
According to a clip created for the Picard family album in Star Trek Generations, which was not used on screen, Jean-Luc Picard wins the Starfleet Academy marathon in April 2323 and graduates on April 20th, 2327 in the Yuri Gagarin Hall. Also included in the album are an invitation to a wine tasting of the Gallic-Klingon Debating Society at Starfleet Academy on April 10th, 2234 and a love letter from Strasbourg dated April 7th, 2328.
In the first draft script of ENT: "Fusion" (which had the working title "Equilibrium"), Charles Tucker III mentioned that April is (at least as of 2151) the time of year when Humans celebrate Earth Day.
Some of the events of the Eugenics Wars novel The Rise and Fall of Khan Noonien Singh, Volume Two take place on April 21st, 1994.
The events of the Pocket DS9 novel Rising Son begin in April of 2376, immediately after those of Avatar, Book Two.