Can I do my sleeping adhkar recite even when I've not ready to sleep because I fall asleep doing other things maybe reading book etc. What's the end time is the rawatib after Isha, can it be delayed till 1/3 of the night ? Ahsanallahu ilaykum

‎The sleep adhkar are said when you lie down in bed to sleep, as the hadiths say “when you go to your bed”. Saying them earlier is not wrong, but it is not the sunnah of the sleep adhkar. The sunnah after Isha lasts as long as the time of Isha.