Ruling on Sawm (fast) on Friday alone

Question 11: Is it permissible to observe Sawm (Fast) on Fridays alone to make up for missed days of Ramadaan?

Answer: The Prophet (peace be upon him) prohibited fasting on Friday alone, if it is done just because of its special virtue: The Prophet (peace be upon him) visited one of his wives on a Friday and she was observing Sawm. He asked her, ‘Did you observe Sawm yesterday?’ She said, ‘No.’ He said, ‘Do you intend to observe Sawm tomorrow?’ She said, ‘No.’ He said, ‘Then break your Sawm.’ In the Two Saheeh (authentic) Books of Hadeeth (i.e. Al-Bukhaaree and Muslim), it is reported from Aboo Hurayrah (may Allaah be pleased with him) that the Prophet (peace be upon him) stated: None of you should fast on Friday unless you fast a day before it or a day after it.... read more here.