Six months validity required on passports (Wed 27 Aug 2014)
AIf you are traveling to Nepal with an American passport, you must have at least six months validity remaining on your passport otherwise you may be denied boarding.
For Nepali passport holders returning to Nepal, this rule does not apply. Nevertheless, we strongly recommend that you get a new passport if the validity period is less than six months.
Although this is a practice started at Dubai, other airports are also following it.