Time of Salah does not occur or Salah time re-enters

Time of Ṣalāh does not occur or Ṣalāh time re-enters

Question

(1) If Ṣalāh time re-enters for example because of travelling on an aeroplane, and a person has already performed Ṣalāh on time, will it be necessary to perform the Ṣalāh again?

(2) In the summer months in the UK, ʿIshāʾ time does not occur. Will ʿIshāʾ Ṣalāh remain obligatory?

The answer to this question is now available on the following link: http://islamicportal.co.uk/time-of-salah-does-not-occur-or-salah-time-re-enters/