That Summer Day is a one-hour docudrama directed by Jon East, written by Clive Bradley (who also wrote Last Rights), produced by Hannah Pescod and executive produced by Jon East and Mark Redhead that provides a fictional account of the lives of six children on the day of the bombings of the London public transport system on 7 July 2005. The drama combines fictional elements and archive footage from television and radio to document the effect the events had on the children. The programme's creation is the result from the correspondence the CBBC website received following the events, from children struggling to come to terms with it. In the early development of the show, the creators visited schools and people from charities like ChildLine, who had talked to children about the subject, to find out which themes and issues the programme needed to address to properly respond to the questions raised by children. The programme was filmed on location in London and at Islington Green School. Several of its students were extras during filming.In the press release announcing the programme, executive producer Mark Redhead said:

We aimed to make a film that would go a small way towards making sense of the events and to explore themes about racial and religious tension, loss and fear, as well as highlighting positives like love, family and friendship.

The racial tensions described becomes apparent when the Muslim character Ayesha is not allowed on the bus by the bus driver because Islamic extremists are suspected to be involved in the attack. Another character, Ben, goes to find his father who travels through one of the affected stations, Liverpool Street tube station, on a daily basis.

The programme was broadcast on BBC Two exactly a year after the events it was based on at 16:30 local time. It was later repeated on the CBBC Channel on Sunday 9 July 2006 at 18:00 local time. The programme is the first fictionalized account of the attacks in the history of British children's television. The programme was repeated on the second anniversary of the bombings on the CBBC Channel at 17:00 local time and on 25 November 2007 the programme received a Children's BAFTA in the category Best Drama.