Abu Hafs Yazid bin Kaysan (may Allah have mercy on him) said: Tawus (may Allah have mercy on him) was asked about a man who swore that he would not speak to a man for a time, and I was present at that time. He said: Zaman (a time) means two or three months, when no term has been fixed. They differ about the hin, and the meaning of hin also differs in its various places; so there is no fixed limit for the word hin when it is used unqualified. The word zaman is likewise.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 20022