Real age of Josh Hartnett in 40 Days and 40 Nights
In the movie 40 Days and 40 Nights, Josh Hartnett was:
23 years old
That was the real age of the celebrity according to our calculation.
The calculation of the shown age took into account the first day of the year in which the movie 40 Days and 40 Nights was released:
January 1, 2002
And the day in which Josh Hartnett was born:July 21, 1978
Since movies usually don't take more than one year to be released since the beginning of the filming process, Josh Hartnett may have been one year younger or one year older than the shown age while some scenes of the movie were being filmed.