Five million English football fans, or one in five of the workforce, are taking a day off work today, with a further 2.5 million taking a "sickie" to watch the vital England vs Argentina World Cup match.
It is 22 years since England beat Argentina, and the stakes were raised by Sweden's 2-1 win over Nigeria.
Many employers have set up giant TV screens at work and are allowing their employees to watch the match during a long lunch break, with some even providing free food for staff.
Law firm Olswang has offered employers guidance concerning the World Cup. "We recommend that a combination of tackling the issue early and working with employees will be crucial in minimising the impact that the World Cup may have on levels of absence and productivity. Employers can of course insist on all employees working normal hours, with disciplinary sanctions if they do not, but this may lead to truancy and/or lower staff morale."
Experts estimate that the tournament will could cost the nation £1.3bn in lost productivity.
Many pubs have a special licence to open at 6am for football fans keen to catch the early action with a pint. Many Web sites, including the official fifaworldcup.com site, are offering text-based commentary for those unable to leave their computers during World Cup games.
The 2.5m people who have called in sick to watch the game risk trouble from certain employers, as this can be seen as "gross misconduct". The 7th of June may be remembered as the worst possible day to be genuinely ill.
Trade and Industry Secretary Patricia Hewitt urged firms to take a "flexible" approach to working hours to avoid disruption during the World Cup. And the general secretary of the GMB Union, John Edmonds, called for companies to give workers half a day off to watch England and Ireland play.