Expressions used in Everyday Spoken English in Social and Professional contexts
The phrase 'the clock is ticking' refers to time moving or running out in order to be able to do something or to avail of an opportunity. If you remind someone 'the clock is ticking' you are informing them that there is a limited period of time in which to do something. This expression is often used to talk about women's 'biological clocks' ticking or the realisation that time is running out for them to have a child if they wish.