Bhagavad Gita 8.25

8.25 Attaining to the lunar light by smoke, night time, the dark fortnight also, the six months of the southern path of the sun (the southern solstice), the Yogi returns.

The mystic who passes away from this world during the smoke, the night, the fortnight of the waning moon, or the six months when the sun passes to the south reaches the moon planet but again comes back.