"This is how Nanda was wakeful. Here, Nanda purified his mind from
obstructing things during the day seated somewhere. Nanda purified his
mind from obstructing things during the first watch of the night
seated somewhere. During the middle watch of the night, turning to his
right he takes the lion's posture keeping one foot over the other and
mindful of the time of rising. Having got up in the last watch of the
night he purifies the mind from obstructing things. Bhikkhus, this is
how Nanda was wakeful."
http://www.mettanet.org/tipitaka/2Sutta-Pitaka/4Anguttara-Nikaya/Anguttara5/8-at\
thakanipata/001-mettavaggo-e.html

Nyanaponika's translation is "keeping his mind on the thought of
getting up"