import toDate from '../toDate/index' ; import requiredArgs from '../_lib/requiredArgs/index' ; name category summary description param { Date | Number } dateLeft param { Date | Number } dateRight returns { Number } throws example export default function differenceInMilliseconds ( dateLeft , dateRight ) { requiredArgs ( 2 , arguments ) ; return toDate ( dateLeft ) . getTime ( ) - toDate ( dateRight ) . getTime ( ) ; }