Is it Islamically forbidden to dedicate a specific day – which marks the anniversary of a salvation from death – to increasing acts of seeking forgiveness (Istighfar), praising Allah (Hamd), and giving charity (Sadaqah), with the intention of thanking Allah for the salvation?

It is prescribed for one whom Allah has saved from an affliction to thank and praise Allah, and to increase in remembrance (dhikr) and seeking forgiveness (istighfar). For deliverance from calamities is a blessing that deserves gratitude. The permissibility of thanking Allah for salvation through whatever acts of worship are easy is indicated by what Al-Bukhari and Muslim narrated from Ibn Abbas, may Allah be pleased with both of them, that the Prophet, peace and blessings be upon him, fasted Ashura in gratitude for the salvation of Musa and his people. Therefore, there is no prohibition against increasing in seeking forgiveness, remembrance, and charity as a thankfulness to Allah for His protection and care on the day He bestowed wellness.