Is it permissible to pray Qiyam al-Layl during the last ten nights of Ramadan at any time between Isha and Fajr for someone who cannot perform the entire Qiyam al-Layl due to work in the morning?

Night vigil (Qiyam al-Layl) is achieved by performing any prayer between Isha and Fajr, though it is best performed in the last third of the night. Whoever prays with the Imam until he departs will have the reward of a complete night vigil recorded for him. It is not from the Sunnah to pray the entire night, as the Prophet, peace and blessings be upon him, did not exceed eleven rak'ahs.