week in, week out

a week from next Tuesday

Some unspecified time in the future.

a week is a long time in politics

In politics, much change can occur in a short space of time.

flavor of the week

A fad; someone or something that is held in esteem or receives attention for a short amount of time.

hell week

The week during which new members are required to undergo undignified rites of initiation or gruelling discipline in order to be accepted into a fraternity, sorority, secret society, military group, etc.

knock someone into the middle of next week

To thoroughly beat or trounce someone.

second Tuesday of the week

A time that will never come.