Yugua Purusha concept of Lord Vishnu is found in certain
Puranas and Vaishnava scriptures. As Yuga Purusha, Vishnu is the lord of time.
Lord Brahma divided Vishnu into the four ages or yugas. The
four yugas are Krita, Treta, Dwapara and Kali. The four Yugas constitute a
Kalpa.
As per this concept, everything in this universe is a part
of Vishnu including time and space.