“Religious obligations” is a very broad term which includes both ritualistic actions that are purely acts of worship and also includes rights and duties between people, and other matters.
What appears to be the case is that what you are asking about in your question is purely ritualistic acts of worship that are to be done within a specific time, such as prayer and fasting. These acts for which the time has expired differ as to whether they can be made up after that or not.
The obligatory acts that can be made up also differ in terms of the circumstances that allow them to be made up or not.
I.
Obligatory acts that must be made up
are individual obligations to be done within a specific time that has now expired for the accountable individual. They are of two types:
i.Those that he missed for a legitimate reason. He must make up these acts, such as when one misses prayer because of sleeping or forgetting, according to scholarly consensus. That is because the Prophet (blessings and peace of Allah be upon him) said: “Whoever forgets a prayer, let him offer it as soon as he remembers, for there is no expiation for it other than that.” Narrated by al-Bukhari, 572. According to a report narrated by Muslim, 684: “If one of you sleeps and misses a prayer, or forgets it, let him offer the prayer when he remembers, for Allah says: {and establish prayer for My remembrance} [Ta-Ha 20:14].”
And fasting is like prayer, because Allah, may He be Exalted, said to those who have legitimate excuses allowing them not to fast: {but if anyone is ill, or on a journey, he should fast the same number of other days} [Al-Baqarah 2:185].
ii.Those that he missed with no excuse.
The scholars differed about making up these obligations.
The majority of scholars are of the view that it is obligatory to make them up, along with repenting for what he incurred of sin as a result of negligence in carrying out obligatory duties at the time required according to Islamic teachings.
An-Nawawi (may Allah have mercy on him) said, after quoting the hadith “If one of you sleeps and misses a prayer, or forgets it, let him offer the prayer when he remembers”: This indicates that it is obligatory to make up a missed obligatory prayer, whether that was because of sleeping, forgetting or any other valid excuse. The hadith only mentions forgetfulness by way of stating that the prayer was missed for a reason, because if it is obligatory for one who had an excuse to make up the prayer, then it is more appropriate that it should also be obligatory for the one who had no excuse.
End quote from Sharh an-Nawawi `ala Muslim, 5/183.
Ibn Daqiq al-‘Eid (may Allah have mercy on him) said in his commentary on the hadith “Whoever forgets a prayer, let him offer it as soon as he remembers, for there is no expiation for it other than that”:
He must make up the prayer if he misses it because of sleeping or forgetting. This is stated in the texts and there is no difference of opinion regarding it...
It also indicates that it is more emphasised for the one who deliberately did not do it that he must make it up, because if there is no letting off for the one who had the excuse of sleeping or forgetting, that implies that it is more appropriate that the one who had no excuse should not be let off.
End quote from Ihkam al-Ahkam Sharh `Umdat al-Ahkam, 1/294-295.
Ibn al-Mulaqqin (may Allah have mercy on him) said:
The hadith indicates that it is obligatory for one who slept or forgot and missed the prayer to make up the prayers, whether the number of missed prayers is great or small. This is the view of all the scholars.
Some scholars held an odd view about the one who misses more than five prayers, and said that he does not have to make them up, as was narrated by al-Qurtubi, but no attention should be paid to this view. But if he omitted the prayers deliberately, then the majority of scholars are of the view that he must make them up, apart from what was narrated from Dawud and a few others.
At-Tawdih li Sharh al-Jami` as-Sahih, 6/287.
Some scholars are of the view that he should not make them up because of his negligence in doing a religious obligation at the specified time, and that failing to do a religious obligation at the time specified cannot be made up at a time other than its specified time, because he will be doing an action in a manner different than that which Allah and His Messenger enjoined, and thus it will be rejected, because of the hadith “Whoever introduces something into this matter of ours that is not part of it will have it rejected.” Narrated by Muslim, 1718.
This is the view of `Umar ibn al-Khattab and his son `Abdullah, Sa`d ibn Abi Waqqas, Salman, Ibn Mas`ud, al-Qasim ibn Muhammad ibn Abi Bakr, Budayl al-`Uqayli, Muhammad ibn Sireen, Mutarrib ibn `Abdillah and `Umar ibn `Abd al-`Aziz. It was also the view of Dawud az-Zahiri (the Literalist) and Ibn Hazm and was the view favoured by Shaykh al-Islam Ibn Taymiyah and ash-Shawkani. Among contemporary scholars, al-Albani, Ibn Baz and Ibn `Uthaymin regarded it as more likely to be correct.
We have previously discussed that in detail, with evidence. Please see the answer to question no. 111783.
Fasting is like prayer, and so are other individual obligations that are to be done at a specific time.
An-Nawawi (may Allah have mercy on him) said:
A missed Ramadan fast is like a missed prayer: if it was missed for a valid reason, such as menses, postpartum bleeding, sickness, unconsciousness or travel, then it may be made up at one’s own convenience, so long as the following Ramadan has not yet begun.
But if it was missed deliberately, then there are two scholarly views, as in the case of prayer. The more correct view according to the Iraqi scholars is that he may make it up at his own convenience, but the more correct of the two views according to the Khurasani scholars and some of the Iraqi scholars, which is the correct view, is that he must make it up immediately.
End quote from Al-Majmu` Sharh al-Muhadhdhab, 3/69).
II.
With regard to acts of worship which are to be done at a specific time but are not obligatory, such as regular Sunnah prayers and supererogatory prayers, we have discussed that in detail on our website, in the answers to questions no. 142425 and 114233.
III.
There are some obligatory individual duties other than purely ritualistic acts of worship, such as financial obligations, which must be done at certain times. These obligations are not waived if a person delays them, and he incurs sin thereby, because they have to do with the rights of other people, such as zakah, spending [on family members] and so on.
To explain all of that would take too long here; what we have mentioned above highlights some basic principles regarding this matter.
To sum up:
If an accountable person fails to do an obligatory action that is to be done within a specified time because of a legitimate excuse, he should do it when the excuse no longer applies. If he did that with no excuse, then he must repent sincerely and make up that obligatory action, as is the view of the majority of scholars, or it may be sufficient to repent without making it up, as is the view of a number of scholars who examined this issue.
But making it up is more prudent, unless what was missed is so much that it would be too difficult to make it up, in which case he may avail himself of the second view.
For more information, please see the answers to questions no. 111783 and 13664.
And Allah knows best.
