Update Mar 17, 2018: The nine-hour rainbow has made it to Guinness World Record for the "longest-lasting rainbow, Taiwanese media reported.
Many people count themselves lucky to catch a glimpse of a rainbow, but they may now have to dispel the notion that the sight only lasts for a fleeting moment.
Two professors in Taipei recently found out that a rainbow may last for as long as nine hours.
On Nov 30, the pair from Chinese Culture University's Department of Atmospheric Science documented what may be the most enduring light show ever.
The rainbow was in the sky from 6.57am to 3.55pm, a duration minutes shy of a full nine hours.
"It felt like a gift from the sky... It's so rare!" one of the professors Chou Kun-hsuan said.
Photos posted on the university's Facebook page showed colourful arches over the campus' Chinese style architecture and lush greenery, which made for an especially scenic sight.
And there was not just one, but four - two primary and two supernumerary - rainbows, according to Chou.
If confirmed, this will become the longest-lasting rainbow recorded, beating the previous record of six hours observed in Yorkshire, England, in March 1994.
To apply for Guinness World Record's "longest-lasting rainbow", the professors are gathering more evidence from those who witnessed the unusual phenomenon on campus that day.