My Japanese textbook only lists じゅっぷん. Our Japanese sensei (a quite old woman) says じっぷん but notes that it's optionally じゅっぷん. Our TAs all say じゅっぷん.
I understand that Middle Chinese 十 was "jip" and the thing went through じふ->じう->じゆう->じゅう, but what about 十分?
Clearly じっぷん seems to be the etymologically correct pronunciation, but which one is the more modern-day official and widespread pronunciation (i.e. more commonly used and accepted), rather than simply historically correct?
Edit: How about １０分? Is the more common pronunciation of １０分 different?