Does "Quit" Mean Resignation Date or Last Day? Clarifying Joining Bonus Terms

This is the sentence in my agreement: 'If I quit within 18 months, the joining bonus is recoverable.' My question is, does "quit" mean the day I resign or my last day? For example, let's say my notice period is 1 month and 18 months complete on 31 August. So, if I resign on 1st August, is my joining bonus recoverable? On the safer side, I want to resign on 1st September, but still, if I can on 1st August, then I will...!!!

This completely depends on a company's policy. However, if we have to infer from the agreement sentence, I think that even if you resign on 1st August and serve until 31st August, then the joining bonus is not recoverable.