Eating or Drinking Forgetfully in Ramadan

Question:    As-salamu `alaykum. I totally forgot that I was fasting and had a cup of coffee when I got to work. Will this break my fast?
consultant:    Ahmad Kutty
Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear brother, thanks for your question. May you have a happy and blessed Ramadan!
It is noteworthy to state that the month of Ramadan is a blessed month and an opportunity for every Muslim to draw near to Allah, to increase his or her morality and spirituality, and to gain abundant rewards.
As far as the Islamic Shari`ah is concerned, any Muslim who forgetfully eats or drinks during the daytime of Ramadan is to complete his or her fast and not to break it .However, he or she has to stop eating and stop drinking from the moment he or she realizes that this is fasting time. The Prophet (peace and blessings be upon him) is reported to have said, “If somebody eats or drinks forgetfully, then he should complete his fast, for what he has eaten or drunk has given to him by Allah” (Al-Bukhari and Muslim)
In his response to your question, Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states,
If you did so forgetfully, then it did not break your fast, as long as you stopped it [eating and drinking] from the moment you remembered that you were fasting. If, on the other hand, you continued to do so even after remembering, then, of course, your fast was broken and you have to make up for the same by fasting another day.
Abu Hurayrah reported that Prophet Muhammad (peace and blessings be upon him) said, “If somebody eats or drinks forgetfully, then he or she should complete fasting, for what he or she has eaten or drunk has been given to him by Allah” (Al-Bukhari and Muslim)
Based on this, scholars are of the opinion that eating or drinking forgetfully does not invalidate one’s fast. It goes without saying that one must immediately abstain from doing so as soon he or she becomes conscious of it.
In conclusion: Your fast is not broken as long as you did not consume anything after recognizing that you are supposed to be fasting.
Allah Almighty knows best.

Source: OnIslam.net & islam.ca