Do Mondays and Thursdays have a special status in Islamic Sharia, such that if one is unable to fast on them, is it legislated for him to increase other acts of worship so that his deeds may be elevated while he is devout to Allah, or are they ordinary days designated only for fasting?

Thursday and Monday are virtuous days when deeds are presented to Allah Almighty and the gates of Paradise are opened. The Prophet, peace and blessings be upon him, encouraged fasting on these days, saying: "Deeds are presented on Monday and Thursday, and I love for my deeds to be presented while I am fasting." On these days, forgiveness is granted to every servant who does not associate anything with Allah, except for those who are quarreling, until they reconcile. It is also recommended to increase good deeds on these days, in addition to fasting, such as increasing remembrance of Allah (dhikr), giving charity, and performing supererogatory prayers, so that rewards may be multiplied.