How is it possible to perform Qiyam al-Layl in Belgium during the summer, given that the duration between the 'Isha and Fajr prayers is very short?

"Qiyam al-Layl is achieved even with the Witr prayer, as stated in the commentary by al-Bujairimi, that Qiyam al-Layl is attained by performing obligatory prayers, whether they are qada' (making up missed prayers) or nadhr (vowed prayers), and by performing time-specific supererogatory prayers, such as the Sunnah of 'Isha' or Witr. We advise the questioner to verify the prayer time, as there might be an error in the calendar."