German future perfect
Rarely used, this tense requires conjugation of a verb's past participle and used with conjugated forms of werden. The infinitive form of the helping verb haben is then put at the end of the sentence.
We will have slept all night: wir werden die ganze Nacht geschlafen haben
We will have played all day: wir werden den ganzen Tag gespielt haben
He will have found it: er wird es gefunden haben.
This tense indicates something that will be completed in the future but conversational German usually contains the simpler versions of future perfect tenses and the future tenses.