Times when it is forbidden to pray

There are times when it is forbidden to pray. They are as
follows: 

From after the fajr prayer until sunrise

From sunrise until the sun has risen to the height of a spear
above the horizon; nowadays this is regarded as equivalent to twelve minutes
after sunrise, but to be on the safe side one should make it a quarter of an
hour.

When the sun is overhead at noon, until it has passed its
zenith

From ‘Asr prayer until sunset

When the sun starts to set until it is completely set 

These times may be summed up more briefly as follows: 

From after fajr (salah) until the sun has risen to the height of a spear

When it is directly overhead at noon until it has passed its
zenith

From ‘Asr prayer until the sun has set completely. 

When we say from fajr, we mean that one should not offer
voluntary prayers after the adhaan of Fajr except the Sunnah of Fajr. This
is the view of the Hanbalis. The Shaafa’is are of the view that the
prohibition has to do with Fajr prayer itself, so it is not forbidden to
offer voluntary prayers between the adhaan and iqaamah, rather it is
forbidden to offer voluntary prayers after offering the obligatory prayer of
Fajr. 

This is the more correct view, but one should not offer any
voluntary prayer after the break of true dawn apart from the two Sunnah rak’ahs of Fajr,
because the Prophet (peace and blessings of Allaah be upon him) only
prayed two brief rak’ahs after (the break of true) dawn had broken. 

See al-Sharh al-Mumti’ by Shaykh Ibn ‘Uthaymeen,
4/160. 

This is indicated by the report narrated by
al-Bukhaari (547) and Muslim (1367) from Ibn ‘Abbaas, who said:  Some
trustworthy men bore witness in my presence, the most trustworthy of whom in
my view was ‘Umar, that the Prophet (peace and blessings of Allaah be
upon him) forbade praying after Fajr until the sun had risen and after ‘Asr
until the sun had set.” 

Al-Bukhaari (548) and Muslim (1371) narrated that Ibn ‘Umar
said: The Messenger of Allaah (peace and blessings of Allaah be upon
him) said: “When the top edge of the sun has risen, then delay praying until
it has risen above the horizon, and when the lower part of the sun has set,
delay praying until it is fully set.” 

Al-Bukhaari (551) narrated that Abu Sa’eed al-Khudri said: I
heard the Messenger of Allaah (peace and blessings of Allaah be upon
him) say: “There is no prayer after Fajr until the sun has risen fully, and
no prayer after ‘Asr until the sun has set.” 

Muslim (1373) narrated that ‘Uqbah ibn ‘Aamir al-Juhani said:
“There are three times at which the Messenger of Allaah (peace and
blessings of Allaah be upon him) forbade us to pray or to bury our dead:
when the sun has clearly started to rise until it is fully risen, when it is
directly overhead at midday until it has passed its zenith, and when the sun
starts to set until it has fully set.” 

And Allaah knows best.