Sa’d bin Ubaidah (may Allah have mercy on him) says that Sayyiduna Ibn Umar (may Allah be pleased with them both) heard a man saying,“Tonight will be the middle of the month.”Sayyiduna Ibn Umar (may Allah be pleased with them both) said:“How do you know that this is the middle of the month? Rather, say that it is the fifteenth date. I heard the Prophet (peace and blessings be upon him) say that sometimes the month is like this, like this, and like this.”The narrator folded the finger the third time which indicates the number thirty.