Based upon the Golden Age character Rex Tyler, he first appeared in JLA #12 (November 1997) and was created by Grant Morrison and Howard Porter.

Shortly after his construction, Metron appoints Hourman as his heir and entrusts him with the Worlogog, an artifact containing a map of space and time.

After restoring the planet Krypton and its inhabitants, Hourman travels to the 20th century to join the Justice League, where Snapper Carr mentors him.

After leaving the group, Hourman gives Rick a tachyon-filled hourglass that can see the future and temporarily resurrects his father, who was killed during the Zero Hour: Crisis in Time!

[6][7] Hourman's body consists of countless nanomachines, enabling him to repair himself if damaged.