|This article does not cite any references or sources. (June 2012)|
UTC−10:30 is an identifier for a time offset from UTC of −10:30.
The air portion of the attack on Pearl Harbor in 1941 began at December 7, 7:48 a.m. Hawaiian Time and December 8, 3:18 a.m. Japanese Standard Time (UTC+09), as kept by ships of the Kido Butai. UTC time in ISO 8601 notation was 1941-12-07T18:18+00:00.