What is incumbent upon one who fasted Ramadan in previous years without intention, and what is the time for the intention, and what should one do if its time has passed?

The majority of scholars stipulate the intention (niyyah) for fasting Ramadan must be made the night before. Its place is the heart, and it is not legislated to utter it verbally. The time for the intention is from after sunset until the appearance of dawn. According to the Malikis, a single intention is sufficient for the entire month's fast, whereas the majority of scholars believe a separate intention is necessary for each day. Whoever fasts cannot have fasted without an intention, for intention follows knowledge, and an act is not valid except with an intention.