zero hour
noun
• the time at which a planned operation, typically a military one, is set to begin.
Similar:
the appointed time,
the appointed hour,
the crucial moment,
the vital moment,
the critical moment,
the moment of truth,
the point/moment of decision,
the Rubicon,
the critical point,
the crux,
the crunch,
Origin:
First World War: from zero + hour.
zero-hours
adjective
• denoting or relating to a contract of employment that does not include a guarantee of regular work for the employee, who is paid only for the hours they actually work.
• "their survey suggested that one million people are employed on low-security zero-hours contracts"
