a closing time - The amount of time you think a boring conversation will end.

The amount of time you think a boring conversation will end. It works for dinner parties, weddings, and relationships that are going nowhere.

'I thought that conversation would end in 5 minutes, but it lasted forever.', @boredguy

'At my wedding, I thought the speeches would be over in 10 minutes.', @weddingfail

'My relationship was over in 2 minutes, but I thought it would last forever.', @relationshipfail