Fasting lasts until the sun sets and is not as some of the Shi’ah say

The time of fasting on which the Muslims are unanimously
agreed and which they have followed from the time of the Prophet (blessings
and peace of Allah be upon him) and his Companions until the present day is
from the break of the true dawn until when the disk of the sun disappears
completely beneath the horizon. This is indicated by the Qur’aan and Sunnah
and definitive consensus of the Muslims. 

Allah says (interpretation of the meaning): “then complete
your Sawm (fast) till the nightfall [al-layl]” [al-Baqarah 2:187].
Al-layl [translated here as nightfall] in the language of the Arabs
starts when the sun sets. 

It says in al-Qamoos al-Muheet (1364): al-Layl:
from the setting of the sun until the break of the true dawn or sunrise. End
quote. 

It says in Lisaan al-‘Arab (11/607): al-Layl:
comes straight after the end of al-Nahaar (day), and starts when the
sun sets. End quote. 

Al-Haafiz Ibn Katheer (may Allah have mercy on him) said in
his commentary on this verse:

The words of Allah “then complete your Sawm (fast) till
the nightfall” imply that breaking the fast at the moment of sunset is a
shar’i rule. End quote. 

Tafseer al-Qur’aan al-‘Azeem,
1/517 

In fact some commentators have pointed out that the use of
the preposition ila (till) in this verse also implies hastening,
because that preposition indicates reaching the end and achieving the goal. 

Al-‘Allaamah al-Taahir ibn ‘Ashoor (may Allah have mercy on
him) said:

Ila al-layl (till the nightfall) means until one achieves
that goal and reaches the night, and the preposition ila is chosen to
indicate that one should hasten to break the fast when the sun sets, because
the preposition ila means that the purpose is achieved then, unlike the
preposition hatta (until). What is meant here is to indicate that the fast
is completed when the night begins. End quote. 

Al-Tahreer wa’l-Tanweer, 1/181 

All of that is supported by what is narrated in
al-Saheehayn from Ameer al-Mu’mineen ‘Umar ibn al-Khattaab (may Allah be
pleased with him) who said: The Messenger of Allah (blessings and peace of
Allah be upon him) said: “When the night comes from here and the day departs
from here, and the sun sets, then it is time for the fasting person to break
his fast.” Narrated by al-Bukhaari (1954) and Muslim (1100). 

In this hadeeth the coming of night from the east and the
disappearance of the disk of the sun below the horizon are mentioned
together, which is something that is well known, because darkness starts
from the East as soon as the light of the sun disappears below the horizon.
Al-Haafiz Ibn Hajar (may Allah have mercy on him) said:

The phrase “when night comes from here” means from the east,
and what is meant is when darkness becomes discernible. In this hadeeth he
mentioned three things, because even though they are interconnected in fact,
they may appear not to be connected, and it may be thought that night is
coming from the east when it has not yet come, because something is covering
the light of the sun; the same is also true of the departure of day. Hence
it is clarified by the words “and the sun sets”, as an indication that it is
essential to confirm that night has come and day has gone, and that these
events occur because of the setting of the sun and not for any other reason.
End quote. 

Fath al-Baari, 4/196 

Al-Nawawi (may Allah have mercy on him) said: 

The scholars said: each of these three things implies the
other two and is interconnected with them. Rather he mentioned them together
because a person may be in a valley and the like in such a way that he
cannot see the setting of the sun, so he relies on the coming of darkness
and the disappearing of daylight. End quote. 

Sharh Muslim, 7/209 

Al-Bukhaari (1955) and Muslim (1101) narrated that
‘Abd-Allaah ibn Abi Awfa (may Allah be pleased with him) said: We were with
the Messenger of Allah (blessings and peace of Allah be upon him) on a
journey and he was fasting. When the sun set, he said to one of the people:
O So and so, get up and make saweeq for us (mix it with water so that we can
drink it). He said O Messenger of Allah, why not wait till the evening? He
said: Dismount and make saweeq for us. He said: O Messenger of Allah, why
not wait till the evening? He said: Dismount and make saweeq for us. He
said: It is still day. He said: Dismount and make saweeq for us. So he
dismounted and made saweeq for them, and the Prophet (blessings and peace of
Allah be upon him) drank it, then he said: When you see that night has come
from here, then let the fasting person break his fast. 

Al-Haafiz Ibn Hajar (may Allah have mercy on him) said: 

This hadeeth indicates that it is mustahabb to hasten to
break the fast and that it is not permissible to refrain from eating and
drinking for any part of the night at all; rather as soon as it is
established that the sun has set, it is permissible to break the fast. End
quote. 

Fath al-Baari, 4/197. 

Moreover, the fact that there is consensus among the Muslims
regarding breaking the fast and eating as soon as one hears the muezzin give
the call to Maghrib prayer when the sun disappears is evidence that this is
the truth and the one who goes against that is following something other
than the way of the believers and has introduced something into the religion
for which he has no proof or reports from the scholars. 

Al-Nawawi (may Allah have mercy on him) said:

Maghrib comes immediately after the sun has set, and this is
something on which there is consensus. Something concerning this was
narrated from the Shi’ah to which no attention should be paid and which has
no basis. End quote. 

Sharh Muslim, 5/136 

In fact, in many of the books of the Shi’ah it mentions that
on which there is consensus among the Muslims concerning this matter. Some
of them narrated from Ja’far al-Saadiq (may Allah have mercy on him) that he
said: “When the sun sets, it becomes permissible to break the fast and it
becomes obligatory to offer the prayer.” End quote. 

Al-Baroojardi narrated from the author of al-Da’aa’im
that he said: We narrated from Ahl al-Bayt — may the blessings of Allah be
upon them all — that there was consensus concerning that which we learned
from the reports from them, that the onset of night which makes it
permissible for the fasting person to break the fast is the disappearance of
the sun beneath the western horizon without any barrier which would prevent
seeing it such as a mountain or wall and the like. When the disk disappears
beneath the horizon, then the night has begun and it is permissible to break
the fast. End quote. 

Jaami’ Ahaadeeth al-Shi’ah,
9/165 

To sum up: what are some of the Shi’ah do now, of delaying
Maghrib prayer and the breaking of the fast until sometime after the sun has
set is contrary to what is indicated by the Holy Qur’aan, the saheeh Sunnah
of the Prophet and the consensus of the Muslims. 

Moreover it is contrary to what they themselves narrated from their Imams! 

And Allah knows best.