The fast of a person who wakes up after the time of Sehri has ended

Normally, before going to bed at night, a person already has the intention to fast the following day. If he was not able to wake up in time for Sehri and woke up past that time, he must not eat and drink because he is already in the state of fasting. It is Sunnah to have Sehri prior to fasting. However, it is not obligatory to do so, although it is not good to fast without having Sehri. So if someone did not wake up and did not have time to have Sehri, his fast is valid. He should not eat and drink under the impression that he is not fasting.

[English version of "Roza de ene personne ki fine levé après sehri" – Al Jamiat – Vol.2 No.11]