running time
From Longman Dictionary of Contemporary Englishrunning timeˈrunning ˌtime noun [uncountable] the length of time that a film or television programme takes to run from beginning to endExamples from the Corpusrunning time• He turns a daunting running time to advantage, crafting each episode into a romantic cliffhanger.• It has had loads of trouble finding a distributor in the United States, no doubt due to its three-hour running time.• Use lined paper for this, and reckon each line as one second of running time.