Biweekly and bimonthly can mean the same thing
because of the prefix bi-, which here can mean “occurring every two” or “occurring twice in.”
Therefore, biweekly can be “twice in a week” or “every other week.”
Bimonthly can also mean "every other week" if it's twice in a month, or it can mean “every other month.”
Ну ambiguity, ну ёб ж твою мать! Не используйте в деловой переписке bi-, договариваясь о периодичности событий.
