Fast on thirteeth, fourtheenth and fiftheenth if you want to fast at any time during a month .

The Prophet Muhammad (PBUH) advised Muslims to fast on certain days during a month. He said that if one wants to fast at any time during a month then they should do so on the thirteenth, fourteenth and fifteenth of that month. This is an important teaching as it encourages Muslims to practice self-discipline by fasting regularly throughout their lives. It also teaches us about moderation in our daily lives as we are encouraged not to overindulge in food or other activities but rather practice moderation in all aspects of life. Additionally, this hadith reminds us that Allah is always watching over us and knows what we are doing even when no one else does.