तमेवाहुर्युगं तज्ज्ञा यत्र धर्मो विधीयते ॥ २० ॥
yaḥ kālaḥ śata-saṅkhyayoḥ
tam evāhur yugaṁ taj-jñā
yatra dharmo vidhīyate
sandhyā — transitional period before; sandhyā-aṁśayoḥ — and transitional period after; antaḥ — within; yaḥ — that which; kālaḥ — duration of time; śata-saṅkhyayoḥ — hundreds of years; tam eva — that period; āhuḥ — they call; yugam — millennium; tat-jñāḥ — the expert astronomers; yatra — wherein; dharmaḥ — religion; vidhīyate — is performed.
The transitional periods before and after every millennium, which are a few hundred years as aforementioned, are known as yuga-sandhyās, or the conjunctions of two millenniums, according to the expert astronomers. In those periods all kinds of religious activities are performed.