Meaning of Imsak and Its Time
Question

In some countries there is a time approximately ten minutes before Fajr which they say is the time of imsak (stopping eating and drinking), when the people usually start fasting and stop eating and drinking. Is what they do correct?
Praise be to Allah.Imsak means to stop eating and drinking when the dawn comes. If some people in some countries stop eating and drinking ten minutes before Fajr, this is not correct. 
Allah has permitted the fasting person to eat and drink until dawn comes . Allah says (interpretation of the meaning): 
“and eat and drink until the white thread (light) of dawn appears to you distinct from the black thread (darkness of night).” [al-Baqarah 2:187]
Al-Bukhari (1919) and Muslim (1092) narrated from Ibn ‘Umar and ‘Aishah that Bilal used to give the adhan at night. The Messenger of Allah (peace and blessings of Allah be upon him) said: “Eat and drink until Ibn Umm Maktum gives the adhan, for he does not give the adhan until dawn comes.” 
Al-Nawawi (may Allah have mercy on him) said: 
“This shows that it is permissible to eat, drink, have intercourse , etc. until dawn comes.” 
Al-Hafiz ibn Hajar said in Fath al-Bari (4/199): 
“One of the reprehensible innovations that have appeared in our times is giving the second adhan approximately twenty minutes before Fajr in Ramadan, and extinguishing the lamps which indicate that it is haraam to eat and drink for those who want to fast. Those who introduced this innovation claim that they are erring on the side of caution with regard to an act of worship.” 
Shaykh Ibn ‘Uthaymin was asked about some timetables which give the time of imsak as being approximately one-quarter of an hour before Fajr. He said: 
“This is a kind of bid’ah (innovation) which has no basis in the Sunnah. Rather the Sunnah is to do the opposite, because Allah says in His Noble Book (interpretation of the meaning): 
“and eat and drink until the white thread (light) of dawn appears to you distinct from the black thread (darkness of night).” [al-Baqarah 2:187]
And the Prophet (peace and blessings of Allah be upon him) said: “Bilaal gives the adhan at night, so eat and drink until you hear the adhan of Ibn Umm Maktum , for he does not give the adhan until dawn comes.” 
This imsak which some of the people do is an addition to that which Allah has enjoined, so it is false. It is a kind of extremism in religion, and the Prophet (peace and blessings of Allah be upon him) said: “Those who go to extremes are doomed, those who go to extremes are doomed, those who go to extremes are doomed.” (Narrated by Muslim, 2670)
And Allah knows best.