By Mike Collett-White
Wednesday's game kicks off in Sao Paulo at 5 p.m. local time (2000 GMT), which is 10 p.m. in the Netherlands.
Given that the game could last more than two hours should it go into extra time and penalties, it may be past midnight back home before the eventual winner is determined.
"I would always allow my children to watch the match, because this is absolutely unique, I think," Van Gaal told reporters at Corinthians arena, where the semi-final takes place.
"Just look at the impact of the World Cup on a global level.
"And, in general, most of the children are on holiday, so I don't think we should deprive them of that. They won't sleep anyway, because they will be so stressed and tense to know whether or not the Netherlands will win that match or not.
"So I would strongly advise parents to let their children watch the match."
Van Gaal hinted that he would not be surprised to see the Argentina match last even longer than the quarter-final, when the Netherlands eventually beat Costa Rica 4-3 in a penalty shootout. The teams were locked at 0-0 after extra time.
"The chances are that it will be later, because I think Argentina is at a level just a notch higher than Costa Rica." (Reporting by Mike Collett-White, Editing by Nigel Hunt)
- Sports & Recreation
- Van Gaal