1 April was celebrated on Earth as April Fools' Day. In 1963, Ian Chesterton sent one of his Coal Hill School students, Little Titch Critchley, to the supplies cupboard for "a left-handed blackboard rubber". Later that morning, Ian started a snowball fight with Mr Okehurst, shouting, "April fool!"
In the huge snowball event, Francis Minto attacked a snowman with a cricket bat — only for his bat to undergo the most damage. Much to the bully's horror, the snowman, barely dented, came to life and attacked him. Somehow, Susan Foreman and Gillian Roberts were blamed for the attack, and were given detention for their supposed crimes.
While they were on the roof performing their duties, the Cold began to attack again. While Susan and Gillian managed to escape (albeit with Gillian getting cut from the broken glass of a window they entered), the boys down below were all killed by the ice, reduced to frozen corpses in scatters of blood.
They reunited with John Brent, when his father arrived. When they tried to explain the situation to Mr Brent, he took it all for an April Fools' joke. It was only when a Cold Soldier destroyed his car to pieces that the man accepted the story. But, not to worry, Gillian had a plan: she would burn down the school. (PROSE: Time and Relative)
In 1988, when the day fell on a Friday, the last publicly-available issue of Aggrotron! was published in Britain. That 55th issue of the comic, which naturally Izzy Sinclair bought on the day, ended on a cliffhanger in which Courtmaster Cruel was about to reveal his true identity. For Izzy, it was a cliffhanger that would never be resolved until she returned to 8 April 1988 with the Eighth Doctor in her young adulthood. (AUDIO: Izzy's Story)