Chapter 2 · The Yoga of Knowledge · Krishna said
Bhagavad Gita 2.69 — Awake when others sleep
या निशा सर्वभूतानां तस्यां जागर्ति संयमी। यस्यां जाग्रति भूतानि सा निशा पश्यतो मुनेः ॥
yā niśā sarvabhūtānāṃ tasyāṃ jāgarti saṃyamī | yasyāṃ jāgrati bhūtāni sā niśā paśyato muneḥ ||
Meaning
What is night for all beings, the self-controlled person is awake to; and what all beings are awake to is night for the sage who truly sees.