AsSalaamu 'alaykum,
12pm is a time that some people have been taught to refrain from praying, particular for those Muslims who eminate from the sub-Indian continent.
The times during the day when it is not permissible to perform salawaat (prayers) are:
1. Just before Noon - i.e. just before the time of Dhur prayer, when the sun is at its highest point of the day. Many people have confused this for 12pm and given it a fixed time throughout the year. But we know that the exact time of noon differs throughout the year - it falls earlier in Winter than Summer. This moment in the day lasts for approximately 5 minutes and can be identified when the sun does not create a shadow. The reason for the prayers' impermissiblilty during this time is not because of Satan, but due to some earlier religions who used to worship the sun at certain times in the day e.g. at its highest point, while it was rising and while it was setting.
2. Between the time of Fajr and Sunrise. This lasts approximately 1hr 20-30 mins.
3. Just before the Magrib prayer, while the sun is setting. Approximately 10 minutes before sunset. However, some scholars say that no salaah (prayer) should be performed after you have prayed salaat-ul-Asr. This is based on a hadeeth of the Prophet - salallaahu 'alayhi wa sallam - where he said that no prayer should be performed between Asr and Maghrib.
An important note here: The 3 times during which prayer is not permissible (as mentioned above) only applies to the supererogatory (Sunnah and Nawaafil) prayers and not the obligatory (Fardh) prayers.
For example, if you wake up late for Fajr, and the sun is rising, then you must still perform the 2 rakaats (units) Fardh prayer, but not the 2 rakaats Sunnah prayer that comes before. The Sunnah can be performed after the sun has risen.
Another example. We know that the Prophet - salallaahu 'alayhi wa sallam - ordered the person who enters the Mosque to perform 2 rakaats Nawaafil prayer before he sits down. However, if he enters during the 3 times where prayer is not permissible, then he does not have to perform these 2 units of Nawaafil prayer for entering the masjid. However, some scholars say that he should still not sit down, and remain standing until the time where prayer is not permissible elapses. On the other hand, there are also scholars who say that the entrant is allowed to sit if he/she enters during this time.
With regards to reading Qur'aan, then there is no evidence to suggest that during these 3 intervals Qur'aan ought not to be recited. Rather, it is from the practices of the Prophet - salallaahu 'alayhi wa sallam - (and recommended by him) and the Companions that they used to engage in the remembrence of Allaah after Fajr up until sunrise, and also between Asr and Magrib for which there is great rewards. And we know to read Qur'aan, either from memory or the mus-haf (book) is from the remembrance of Allaah - subhaan wa ta'aala - thus there is much reward in this as well as elevating ones 'eemaan.
... and Allaah knows best.
Jazaakillaah khair.