Tokyo is five time zones west of Honolulu, and across the International Date Line, so if it's 10:00 on the 14th at Pearl Harbor it's 05:00 on the 15th in Tokyo. I believe the extended section of the time zone around Hawaii includes Midway, so officially Midway time is the same as Pearl.
http://www.worldtimezone.com/
It's funny - in SH3 the time was always GMT, not base time. Holding the cursor over the time would give you the local time and date. In SH4 this is broken.
