What is the authenticity of the daily Ramadan supplications (duas) circulated on websites and forums, including the supplication: "O Allah, make my fasting therein the fasting of those who fast, and my standing therein the standing of those who stand, and awaken me therein from the sleep of the heedless, and grant me my sin therein, O God of the worlds, and pardon me, O Pardoner of sinners"?

This supplication has no basis in the Sunnah, and most of its wording is unclear. It is permissible to supplicate with any good words that contain no forbidden elements, but it is not permissible to restrict it to a specific time, because restricting acts of worship requires evidence, otherwise, it would be an innovation (bid'ah). Additive innovations include committing to specific acts of worship at specific times that were not prescribed by the Sharia.