It's a date that is for ever fixed in the memory of Adrian Hume. On 9 July 2009, he was looking out of the window of his office at the courier firm he runs from home on the outskirts of Maidenhead in Berkshire when two smartly dressed men made their way up the drive.
The men were from the Ministry of Defence and had come to tell him that his 22-year-old son, who was serving with the 5th Battalion the Rifles in Helmand province, Afghanistan, was dead. Daniel Hume was on foot patrol securing ground for local people to vote in the forthcoming Afghan presidential election, his father proudly tells me, when an improvised explosive device set to destroy a nearby armoured vehicle exploded, killing Daniel almost instantly and severely injuring his comrade Sergeant John Bolam, who was walking alongside him.
At the time, Daniel, who was a bricklayer before joining the Army and had passed out at Catterick barracks as top student only months before, was described by his commanding officer, Lieutenant Colonel Rupert Jones MBE, as "a young man with extraordinary talent and a real thirst for life... with a depth beyond his years". Adrian and Wendy Stafford, Daniel's mother, released a statement: "His death has left a huge void in our lives, we are fiercely proud of him."
His parents did not retreat into their grief, though. Wendy spearheaded a family campaign that has raised nearly £250,000 for Help for Heroes and Care for Casualties, a charity established to help injured soldiers from Daniel's regiment. Meanwhile, Adrian visited Daniel's friends recovering from wounds at Selly Oak military hospital, cycled for the campaign across France's First World War battlefields with some of his son's former squad mates, and fulfilled his and Daniel's shared dream of taking their passion for motorsport to the track.
Two and a half years later, Adrian's grief is still there for all to see as the self-described "proud father" tells me all about Daniel's short life, with his picture grinning down on us from spotless display cabinets and framed photographs above.
"Daniel and I were very, very close," Adrian says as we take a seat in his lounge. "Of course I'm close to all of my children but we were best friends as well as being father and son. I used to be a competitive mountain-bike rider and from the age of 13 Daniel was a downhill rider too. He went on to race for Mountain Bike UK at World Cup level and was number three in the country. So we'd travel across Europe in a motorhome to go to competitions and events. Back home we did everything together at weekends and I was welcomed into his group of friends. So of course his death hit me very hard."
Before Daniel deployed to Afghanistan in mid-2009, his parents had attended an open day run by the Rifles to prepare them for the challenges ahead. "They'd told us the only time someone would come knocking at the door rather than contacting us by phone would be if the worst had happened," he explains. "My sales manager saw the two officers first, they weren't in uniform and he said to me that they looked like a couple of Mafia coming up the drive. He led them in and as soon as they explained they were from the Army I knew the worst had happened. I went into shock and the next six or seven hours are a blank, really."
A family liaison officer from Daniel's regiment was assigned to the family to guide them through the process of repatriating his body, the subsequent inquest and to help them to come to terms with their grief. He explained that Daniel died taking part in Operation Panther's Claw, one of the British Army's largest operations of modern times. His body was repatriated to the now-Royal town of Wootton Bassett, along with seven other soldiers who died within 24 hours of Daniel's death.
While Daniel's friends, comrades and a large chunk of the British media were camped out in Wootton Bassett awaiting his funeral cortège, Adrian and Wendy were attending a repatriation ceremony at nearby RAF Lyneham, where Daniel's body had landed.
"His repatriation was like surviving a boxing bout then being sent straight into the ring to do it all over again," Adrian recalls. "We arrived and met dignitaries, then officers from the Rifles, then the regimental pastor came to give us advice. We actually met Price Edward, who was there to represent the Royal Family."
Despite the media storm throughout the summer of 2009 over the lack of equipment and helicopters being provided for the troops in Helmand, Adrian isn't angry about his son's death: "At the repatriation the regimental pastor explained to me that anger was part of the grieving process, but I'm not an angry person and I won't allow myself to be angry with the Army. In fact, later on I met General Dannatt, the then-Chief of the General Staff, when I was visiting Daniel's wounded friends at Selly Oak and he asked me whether Daniel enjoyed army life. I said yes, and he replied solemnly that 'He won't be forgotten.' It's a lovely sentiment and one that was clearly genuinely meant.
"I know it's strange but if my youngest son wanted to join the Army today, I'd be hard-pushed to dissuade him. Daniel loved the life it gave him and genuinely believed in what he was doing in Afghanistan. He wanted to go out there for another tour after he came home. He was just unlucky."
After Daniel's death, his father admits his attitude to life changed. "I look at my life differently now. Daniel didn't plan for the future or what it holds, he was very much a person for living life to the full, and I think that's one of the characteristics I took on board when I lost him. When he was alive, the two of us always dreamt of taking our love for bikes and moving on to four wheels at some stage. With his death it felt like unfinished business."
Adrian is clearly not the retiring type and when he was introduced to the Caterham Academy – a race programme where a novice racing driver can build their own road-legal sports car to compete over seven races – he leapt at the chance. His car, which cost around £20,000 with race fees, arrived in November 2010 and Adrian's first race, in Daniel's memory, was in April last year.
"The first meeting was very strange. I was used to travelling to motorsport and bike events with Daniel, and to be on my own in the motorhome and on the track was tough. I thought about Daniel on many occasions. It's helped me manage. Wendy has her fundraising and I helped with that, but keeping busy and making the most out of life is the best way I can remember Daniel."
One minor prang aside, Adrian finished the season intact and hopes to go back at a higher ranking later this year. "Daniel is always with me," he says. "He was a bit of a petrolhead and I've taken the registration plate from his old Fiesta and put it on my car. His army mates called him Happy Hume so I've stuck a smiley face on there, too."