FVPV

Basic EPS has 'weighted average number of common shares outstanding' as its denominator

Diluted EPS has 'weighted average number of common shares outstanding' plus 'common shares issued upon assumed conversion/exercise of any potentially dilutive securities' as its denominator.

Also, if a potentially dilutive security is issued during the year, the 'number of common shares issued upon their assumed conversion' is also weighed for the fraction of the year that these securities were outstanding.