Just to help, I understood the time to be: 14 SEP 2015 @ 9:51 UTC.

https://www.ligo.caltech.edu/news/ligo20160211

“The gravitational waves were detected on September 14, 2015 at 5:51 a.m. Eastern Daylight Time (09:51 UTC) by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA.”