Making Up Missed Days of Ramadan

Making up missed days of Ramadan is an obligation that need not be
fulfilled immediately because the time for fulfilling is very wide and one
may perform it at any time. This is also the case with the fast of
expiation (the act of making atonement: if one intentionally breaks his/her
fast). It has been authentically reported that 'Aishah (may Allah be
pleased with her)would make up her missed days during the month of
Sha'ban (the month preceding Ramadan), and that she did not perform them
immediately even if she had the ability to do so.

Observing the fast of Ramadan and making up the days are the same with
respect to the fact that if one day of Ramadan is missed, then only one
day needs to be made up. There is no additional penalty. Scholars
differ about the fact that when a person makes up the missed days he need
not do so on consecutive days. This is because Allah says: "For him who
is sick or on a journey, [the same] number of other days"--that is,
whoever is sick or traveling and breaks the fast must fast the same number
of days that he missed, consecutively or inconsecutively. Allah has
ordered the fast in a general manner without any restricting clauses.

As for making up the missed days of Ramadan,ad-Daraqutni recorded from
Ibn 'Umar that the Prophet said: "If you wish, make them on
nonconsecutive days and if you wish on consecutive days." If one delays performing
the missed days of fasting until the next Ramadan comes, he is to fast
the present Ramadan and then make up the days from the previous
Ramadan. There is no ransom payment to be made, regardless of whether the
person delayed the fasting due to some acceptable excuse or not.

Places where the day is extremely long and the night is short

Scholars differ about what the Muslims who are in areas where the day
is extremely long and the night is short should do. What timings should
they follow? Some say they should follow the norms of the areas where
the Islamic legislation took place--that is, Makkah or Madinah. Others
say they should follow the timings of the area that is closest to them
which has normal days and nights.

Source: Fiqh-us-Sunnah by Sayyid Saabiq; Volume 3: Zakaat and
Fasting. (http://www.usc.edu/dept/MSA/law/fiqhussunnah/fus3_56.html)