When were acts of worship prescribed, and what is the meaning of recalling old missed obligations?

Worship includes many things. Here we mention the dates some of them were mandated: Prayer was mandated on the night of the Isra’ before the Hijra in Makkah. Zakat was mandated in the second year of the Hijra. Fasting Ramadan was mandated in Sha'ban of the second year of the Hijra in Madinah. As for Hajj, there is disagreement regarding the date of its mandation. Missed prayers (fawait) are prayers that were forgotten, or performed in an insufficient manner, or intentionally left out of laziness until their time had expired.