Reference: Fataawa Ramadhaan – Volume 1, Page 165, Fatwa No. 98;
Fataawa Shaykh Ibn ‘Uthaymeen – Volume 1, Pages 474-475
Question: Is a firm intention to break the fast without actually eating or drinking break the fast?
Response: From that which is known, is that fasting is a combination of both the intention and leaving all things that nullify the fast. A person’s intention when fasting, is to bring himself closer to Allaah by leaving all things that will break his fast.
So if a person has made a firm decision to break his fast, then the fast is broken. However, if this is in the month of Ramadhaan, then it is obligatory upon him to refrain from eating until sunset. This is because anyone who breaks the fast in Ramadhaan without a valid reason, has to refrain from eating the rest of that day and it is also upon him to make up for this day [by fasting that which he has missed, once Ramadhaan has passed].
However, if he is not firm in his decision and hesitates, then the scholars have differed [in opinion] in this. Amongst them some have said that the fast is nullified because hesitation is contradictory to a firm decision. And others have said that the fast is still valid because the original state is the presence of an intention to fast, until a firm decision is made to break and cancel it.