The condition he put in his vow came to pass, but    it was not exactly what he had in mind
Question

A person vowed that if his work contract was renewed, he would give a certain amount in charity. In his mind he meant that this was if it was renewed for a year, but it turned out that his contract was renewed for three months. He did not utter the words “one year”. Is he under any obligation?
Praise be to Allah.We put this question to Shaykh Muhammad ibn Saalih al-‘Uthaymeen, may Allaah preserve him, who answered as follows:
No, he is not under any obligation. And Allah knows best.