What is the ruling on making up for missed Ramadan days in winter, when its days are short?

The days of Ramadan on which one did not fast must be made up before the next Ramadan, due to the Almighty’s saying: (And whoever is ill or on a journey - then an equal number of other days). It has been authentically reported from Aisha, may Allah be pleased with her, that she would not make up what she owed except in Sha'ban, due to the Prophet's, peace and blessings be upon him, position.