Almighty Allah Subhanahu WA Ta’aala (GOD) says in the Qur’an: "Verily, Salah is enjoined upon believers at FIXED hours".
Any deviation from this direct command will be considered unlawful!
Some Scholars are of the opinion that one can combine prayers [out of its stipulated time], but the condition for this is that you have to be on a journey, be ill or really bad weather.
If you belong to the Hanafi Madhhab you are not allowed to even combine prayers regardless of any situation, be it journey, illness etc. the only situation your allowed to combine prayers out of its stipulated time is intense Jihad.
but if your condition is so bad that you have missed your prayers then the best thing for you to do is practice Jamaal as-Suri [apparent combining]
this is when you pray for example Zuhr just before the end of Zuhr [the time of Zuhr finishes] then as soon as it hits 'Asr you will pray 'Asr. In the literal sense you are combining but at the same time you are not conflicting with the Zuhr [literal] verse in the Qur’an which tells the believers to pray the prayers at its specified time.
As Muslims we should strive to pray all our Prayers on time and with Jam'aah. Insh’Allah.
one time. Every Salah must be performed in its prescribed time.
Apparent joining of two Salahs is permissible, not real joining. Apparent
joining is to, for example, delay Zuhr Salaah until before its expiry time
and perform Asr Salaah immediately upon Asr Salaah time setting in. the same
may be applied for Maghrib and Isha Salahs.