No, August is the only month that doesn't have a national holiday (in the US).
September.
There is no month long holiday in Islam. Even the month of Ramadan, that is the month of fasting, it is a working month and a month long holiday.
May
February is black history month but its not really considered a holiday
One holiday is the month of Ramadan.
Veterans Day is celebrated on the 11th of November.
May Day is the most common holiday in the month of May. Although this holiday is not widely celebrated, it is still an important holiday with historical significance.
In the united States, Labor Day is defined as the first Monday in September.
August
there is a two-month holiday for schoolchildren in France.
I'm pretty sure that the most celebrated holiday in I ndonesia is a holiday called fasting month of Ramadhan.