In the intervening time is a phrase used to describe a period of time between two events. It can be used to refer to a period of time that has already passed, or a period of time that is yet to come. SINCE and MEANWHILE are two words that are often used to describe this same concept. SINCE is a word used to describe a period of time that has already passed, while MEANWHILE is a word used to describe a period of time that is currently happening.