One verse

Srimad Bhagavatam 3.11.34

3.11.34

यदर्धमायुषस्तस्य परार्धमभिधीयते । पूर्व: परार्धोऽपक्रान्तो ह्यपरोऽद्य प्रवर्तते ॥ ३४ ॥

yad ardham ayusas tasya parardham abhidhiyate purvah parardho ’pakranto hy aparo ’dya pravartate

yat
that which
ardham
half
ayusah
of the duration of life
tasya
his
parardham
a parardha
abhidhiyate
is called
purvah
the former
para-ardhah
half of the duration of life
apakrantah
having passed
hi
certainly
aparah
the latter
adya
in this millennium
pravartate
shall begin.

The one hundred years of Brahma’s life are divided into two parts, the first half and the second half. The first half of the duration of Brahma’s life is already over, and the second half is now current.