Starting today until August 15, many Muslims will pick six days to fast. These six days of fasting together with the Ramadan fasts, are equivalent to fasting “perpetually,” according to Sahih Muslim. The reasoning behind this tradition is that a good deed in Islam is rewarded 10 times, hence fasting 30 days during Ramadan and six days during Shawwāl is equivalent to fasting the whole year in terms of reward. It is a common misconception that the six days of fasting must be undertaken on consecutive days, but there is no hadith that support or stipulate this.
Masjid Abu Bakr Al Siddiq encourages you to choose six days (on the weekends, for example) to fast before Shawwāl‘s end on Aug. 15.
Learn more about the fasting of six days of Shawwāl here and here.