In which Islamic month Nafal prayer is equal to Farz prayer?

In which Islamic month Nafal prayer is equal to Farz prayer?

کس اسلامی مہینے میں نفل نماز فرض نماز کے برابر ہے؟
Explanation

Nawafil (optional) prayers in Ramadan become equal to Sunnah Prayers Fardh Prayers.