I have two questions.
1) What are the rulings for naming a child? 2) My in-laws follow this custom, that once a boy is born the circumcision is done only on 10th Muharram. What are the rulings for this? They say once someone tried to go against it and the life of the child was at sake.
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger, may Allah exalt his mention as well as that of his family and all his companions.
There are some rulings related to naming a newborn child:
Firstly: The newborn baby should be given a beautiful and appropriate name.
It is the child's right to be named by his parents with a name which is beautiful and it is not forbidden by Islamic Law, like for example a name which is related to worshipping something beside Allah, The Almighty, or a name which contains some attributes or characteristics that are exclusive to Allah. Of course, all of this is forbidden.
Prophet Muhammad said: "The dearest names to Allah are 'Abdullaah and Abdur-Rahmaan." [Abu-Daawood]
It is preferable to name your child after the names of Prophets and Messengers, may Allah exalt their mention, because Prophet Muhammad named his newborn son Ibraaheem; he said: "I named him after my father's name, Ibraaheem." [Muslim]
Also, Prophet Muhammad named the child of the companion 'Abdullaah Ibn salaam, after Prophet Yoosuf, may Allah exalt his mention. [Al-Bukhari] He also gave the name Ibraaheem to the son of Abu Moosaa Al-'Ash'ari. [Bukhari and Muslim]
Secondly: The naming should be:
1. On the seventh day after the child's birth as the Prophet Muhammad said: "Every child bonds to his/her 'Aqeeqah, (i.e. his dutifulness to parents and him being protected by Allah and blessed is subject to his parents slaughtering) which should be slaughtered on the seventh day (after the birth), and on that day he (she) should be named and his (her) hair should be shaved off." [Ahmad]
2. On the first day after the child's birth. Prophet Muhammad said: "Tonight a son was born to me and I named him after my father's name, Ibraaheem." [Muslim]
Regarding the time of circumcision, Ash-Shaafi'ee scholars said that it is recommended for a newborn child to be circumcised on the seventh day after his birth based on two narrations but both are weak.
On the other hand some of our Salaf (who lived in the first three generations after Prophet's migration to Madeenah) say that circumcision on the seventh day is not recommended, because it is a practice of the Jews. This is the opinion of Al-Hassan and Maalik .
Ibn Al-Munthir said: 'There is nothing regarding this issue – circumcision on the seventh day – which proves its prohibition nor is there any report which proves this practice, or (even in) 'Sunnah', nothing at all. Everything is permissible, and it is not allowed to forbid something except with evidence, we do not know who forbade circumcision on the seventh day.'
Believing that circumcision should be on the tenth day of month Muharram, or seeing an evil omen if a child is circumcised on other days is indeed forbidden. This kind of belief is pessimism, while Prophet Muhammad said: "Not from us, he who sees an evil omen (in something), or if somebody does something in which he sees an evil omen." [At-Tabraani, Al-Bazaar]
In addition, choosing a particular day (for circumcision) which is not specified by Islamic Law is an innovation. Prophet Muhammad said: "Whoever innovates in this matter (Islam) of ours anything which is not a part of it, will have it rejected." [Bukhari and Muslim]
So believing in such things without a legal source from Islamic legislation and strong evidence is nothing but Satan's work and the work of ignorant people. It is their duty to fear Allah, The Almighty, and to repent to Him for false belief, because Allah is the only one who can benefit or cause harm.
Allah Knows the best.